P is for Practical PerlMonks

### Re^2: fork method

by manoj_speed (Prior)
 on Sep 07, 2017 at 08:52 UTC ( #1198834=note: print w/replies, xml ) Need Help??

in reply to Re: fork method
in thread fork method

```
Write a program with try-except to get two numbers as input from the u
+ser and do division operation.
- Use try block to get input from the user and do the division of num
+bers.
- Declare except handler for ZeroDivisionError and generate NameError
+ with "ZERO DIVISON ERROR" message inside it.
- Declare default exception handler and print the error message "ERRO
+R CAUGHT !!!" and exit the program.
- The program should always print "Program completed..." message at l
+ast irrespective of any errors.

Scenario 1:
Input:
Enter the number1: 100
Enter the number2: 5
Output:
The division of 100 and 5 is 20
Program completed...

Scenario 2:
Input:
Enter the number1: 100
Enter the number2: 0
Output:
Program completed...
Traceback (most recent call last):
File "C:/Users/Test/Desktop/exception.py", line 8, in <module>
raise NameError("ZERO DIVISION ERROR")
NameError: ZERO DIVISION ERROR

Scenario 3:
Input:
Enter the number1: welcome
Output:
ERROR CAUGHT !!! (<class 'ValueError'>, ValueError("invalid literal
+ for int() with base 10: 'asdfg'",), <traceback object at 0x05336DA0>
+)
program completed...

Write a module named "calc.py" with below declaration and do below ope
+rations.
Declare two variables: x=100, y=200
Declare two functions: addition(a,b),  multiply(a,b,c)
Print the declared variables and call functions[Ex: addition(50, 60)
+& multiply(2, 3, 5)] in main namespace
Declare documentation for calc module

- Import calc module and call addition() function with x and y values
+ from module
- Import x variable and multiply() function from calc module and call
+ multiply() function with x,2,3 as arguments
- Print the documentation for calc module

Write a package named "Phone"
Write a package named "Food" with below details
Food/fruit.py
Declare myfruits list with some fruit names such as apple, orange, e
+tc.
Declare showFruits() function which will display all the fruits in f
+or loop.

Food/vegetable.py
Declare myvegetables list with some vegetable names such as carrot,
+tomato, etc.
Declare showVegetables() function which will display all the vegetab
+les in for loop.

Food/snacks.py
Declare mysnacks list with some snacks names such as biscuit, chocol
+ate, etc.
Declare showSnacks() function which will display all the snacks in f
+or loop.

Food/__init__.py
Import snacks module
Import showVegetables() function from vegetable module
Import all variables and functions from fruits module

Import the Food package and check the access level for variables and
+functions. (Direct & Sub-level)
- Print all the variables (myfruits, myvegetables & mysnacks)
- Call all the functions  (showFruits, showVegetables & showSnacks)

Write a class named "Employee" and "Company" with below details.
Company:
Declare constructor and store "company_name" and "company_location"
+details. (static)
Declare a function named "showCompany()" which will display the comp
+any details.

Employee: (Inherit 'Company' class)
Declare constructor and store "empid", "empname" and "department" de
+tails. (Dynamic)
Declare a function named "showEmployee()" which will display employe
+e details.

Create an object for 'Company' class and display company details.
Create an object for first Employee and display employee and company
+details. (1001, Manoj, IT)
Create an object for second Employee and display employee and company
+ details. (1002, Suresh, Sales)
Change the department & company_location for second employee and disp
+lay the details again.

Write a program to get a sentence as input from the user and display t
+he number of digits, alphabets and special characters.
Input:
Enter the sentence: Welcome to PYTHON. My number is 1234567890. END!
+!!
Output:
Given sentence: Welcome to PYTHON. My number is 1234567890. END!!!
Character  Count
---------  -----
DIGITS     10
UPPER      11
LOWER      17
SPECIAL    12

Write a program to find the below math formulas. (using functions)
Area of square (a*a)
Area of circle (PI * r*r)
Area of Triangle (1/2 * b*h)
Area of Rectangle (w * h)

Write a program to calculate the Celsius to Fahrenheit & vice versa. (
+using functions)
Input:
Heat Calculator
***************
1. Celsius to Fahrenheit
2. Fahrenheit to Celsius
Choose your option [1-2]: 1
Enter the celsius: 5

Output:
Celsius: 5
Fahrenheit: 41

Write a program to print the ASCII value of given characters.
Input:
Enter the string: Welcome Python!
Output:
Given string:
ASCII Characters:
W -> 87
e -> 101
l -> 108
c -> 99
o -> 111
m -> 109
e -> 101
-> 32
P -> 80
y -> 121
t -> 116
h -> 104
o -> 111
n -> 110
! -> 33

Write regex to match the given pattern??

-------------------------------
Python
------
http://www.diveintopython3.net/special-method-names.html

https://jcalderone.livejournal.com/32837.html

# 5a. Decrypt method
import re
+.v.c -> msalesforce1rypt(s, mydict):
l = list(mydict.keys())
result = ''
for i in range(0, len(l)):
mystr = l[i]
if mystr == s:
result += "'%s', " %(mydict[mystr])
else:
if s.startswith(mystr):
mystr1 = mystr
mystr1_d = mydict[mystr]
for i in range(0, len(l)):
if mystr1+l[i] == s:
mystr1_d += " %s" %(mydict[l[i]])
result += "'%s', " %(mystr1_d)
elif s.startswith(mystr1+l[i]):
mystr2 = mystr1
mystr2_d = "%s %s" %(mydict[mystr1], mydict[l[i]])
for k in range(i, len(l)):
if mystr2+l[k] == s:
mystr2_d += ' %s'%(mydict[l[k]])
result += "'%s', " %(mystr2_d)
elif s.startswith(mystr2+l[k]):
mystr2 += l[k]
result = re.sub(', \$', '', result)
#print("RES: [%s]"%(result))
return '['+result+']'

print(" decrypt() method ".center(50, '*'))
print(decrypt('turing', {'turing': 'A', 'tur': 'B', 'ing': 'C', 'tu':
+'D', 'ring': 'E', 'ri': 'F', 'ng': 'G'}))

# 1. check anagram
def check_anagram():
anagram_list = []
mydict = {}
fp = open('C:/Users/v531997/Desktop/words.txt', 'r')
for line in fp:
line = line.rstrip()
mydict[line] = False

myresult = {}
sorted_keys = sorted(mydict.keys())
for i in range(0, len(sorted_keys)):
for j in range(i+1, len(sorted_keys)):
if mydict[sorted_keys[j]] == False and (sorted(sorted_keys[i]) =
+= sorted(sorted_keys[j])):
mydict[sorted_keys[i]] = mydict[sorted_keys[j]] = True
if sorted_keys[i] in myresult.keys():
myresult[sorted_keys[i]].append(sorted_keys[j])
else:
myresult[sorted_keys[i]] = [sorted_keys[i], sorted_keys[j]]

for k in mydict.keys():
if mydict[k] == False: myresult[k] = [k]

for i in reversed(sorted(myresult.values(), key=len)): print(' '.joi
+n(i))

print(" Check Anagram ".center(50, '*'))
check_anagram()

# Skip Until
def skip_until(p,iterable):
iterable = iter(iterable)
skip_flag = True
for j in iterable:
if skip_flag:
if p(j):
skip_flag = False
yield(j)
else:
yield(j)

print(" Skip Until ". center(50, '*'))
for i in skip_until(lambda x: len(x) > 1, ['x', 'y', 'abc', 'a', 'xyz'
+]): print(i)

# Linked list reverse
class LN:
def __init__(self, value, next =None):
self.value, self.next = value, next

def str_ll(ll):
while ll != None:
ll = ll.next
return answer + 'None'

def reverse(ll):
if ll == None:
return None
prev = None
curr = ll

while (curr != None):
next = curr.next
curr.next = prev
prev = curr
curr = next
ll = prev
return ll

print(" Reverse Linked List ".center(50, '*'))
l1 = LN(1, LN(2, LN(3)))
print(str_ll(l1))
print(str_ll(reverse(l1)))

# Sum of Binary tree
class TN:
def __init__(self, value, left=None, right=None):
self.value, self.left, self.right = value, left, right

def sums(t):
if t == None:
return 0
return sums(t.left) + t.value + sums(t.right)

tree = TN(6, left=TN(3, right=TN(2)), right=TN(8, left=TN(7), right=TN
+(9)))
print(" Sum of Binary Tree ".center(50, '*'))
print(sums(tree))

==================
CGI
#!C:\Python27\python.exe
# httpd.conf
# Options +Indexes +FollowSymLinks +Multiviews +ExecCGI
# AddHandler cgi-script .cgi .py

import cgi
import os

def TestPage():
print """
<html>
<title>Welcome to Python</title>
<body>
<h3>Welcome to Python CGI</h3>
<h4>This is my test page.</h4>
</body>
</html>
"""

def EnvPage():
print "<html><body bgcolor='lavender'>"
if os.environ['QUERY_STRING']:
for myvar in os.environ['QUERY_STRING'].split('&'):
(name, value) = myvar.split('=')
print "<font size=3><b>{0}  -->  {1}</b></font><br>" .format(nam
+e, value)

print "<center><h3>Environment Variables</h4></center><br>"
for k in sorted(os.environ.keys()):
print "<b>%20s</b>: %s</br>" % (k, os.environ[k])
print "</body> </html>"

def FormPage():
print "<html><body bgcolor='lavender'>"
form = cgi.FieldStorage()
first_name = form.getvalue('first_name')
last_name  = form.getvalue('last_name')
if first_name:
print "<h2>Hello %s %s</h2>" % (first_name, last_name)

print """
<form action = "/cgi-bin/sample.py" method = "post">
First Name: <input type = "text" name = "first_name"><br/>
Last Name : <input type = "text" name = "last_name"/>
<input type = "submit" value = "Submit" />
</form>
"""

print "Content-type: text/html\n"
#TestPage()
#EnvPage()
FormPage()
==================
Django Setup
------------

> python -m django --version

Sqlite3:
-------
> sqlite3   [<filename.db>]
.databases
.tables
.schema <tab_name>
select * from <tab_name>  [List entries without header]

.show  [To display all default settings]
.header on   [Try above query, will print header also]
.mode column [To display output in column space separated, instead of
+ "|" separator]
.timer on  [To dislay the time taken to execute the query]
.exit

To take dump,
> sqlite3  MyTestDb.db .dump > MyTestDB.sql
To restore from dump,
> sqlite3  MyTestDb.db < MyTestDB.sql

To list all tables in database,
> SELECT tbl_name FROM sqlite_master WHERE type = 'table';
> select sql from sqlite_master WHERE type = 'table' and tbl_name = '
+sample';
> select current_timestamp as "CURRENT TIME";
> select strftime("%d/%m/%Y %H:%M:%S  %s", 'now')
> alter table sample add mydate text;
> update sample set mydate = datetime('now', 'localtime')
> select datetime(1518599385, 'unixepoch', 'localtime')

-------

> django-admin startproject MySite
> cd MySite
> python manage.py runserver 8080

To Create an application,

> python manage.py startapp myfirstapp
* Change file myfirstapp/views.py,
from django.http import HttpResponse

def sample(request):
return HttpResponse("<h2>Hello, world!<h2> <h3>Welcome to  Django
+Application.</h3>")

* Create a file myfirstapp/urls.py,
from django.urls import path
from . import views

urlpatterns = [
path('', views.sample, name='sample'),
]

* Change file MySite/urls.py
from django.contrib import admin
from django.urls import path, include

urlpatterns = [
path('testapp/', include('myfirstapp.urls'))
]

* Start the service,
> python manage.py runserver 8080
Try URL,
http://localhost:8080/testapp

Database Setup,
Goto MySite/settings.py
- Change TIME_ZONE entry and database details. {Default SQLite]

# python manage.py migrate

To create super user,
> python manage.py createsuperuser

=============

# pip install pillow

===========
class  MyTestClass():
a=100

def __init__(self, funcname):
exec("self.myval = funcname" .format(funcname=funcname))
exec("self.{name} = 100; self.get_{name} = lambda : 12345 " .fo
+rmat(name=funcname))
#exec("""def mytest(self): print("MYTEST FUNCTION")""" .format(
+self=self))
#exec("self.{name} = 100; get_{name} = lambda : self.{name}" .f
+ormat(name=funcname))

self.keywords = ['False', 'None', 'True', 'and', 'as', 'assert'
+, 'break', 'class',
'continue', 'def', 'del', 'elif', 'else', 'except', 'finally',
'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda',
'nonlocal', 'not', 'or', 'pass', 'raise', 'return',
'try', 'while', 'with', 'yield']
print("Class object created.")

#def __str__(self):
#    print("String method: ")
#    return "STRING: "

def checkKeyword(self, keyword):
match = 'not'
if keyword in self.keywords:
match = ''
print("Given word [%s] is %s a keyword." %(keyword, match))

def checkIdentifier(self, name):
## Use try / except to check NameError or SyntaxError
isValid = False
if str(name).isidentifier() and not str(name).startswith("_")
+and name not in self.keywords:
print("Valid identifier [%s]" %(name))
else:
print("Invalid identifier [%s]" %(name))

def myfunc(self):
print("This if myfunc() function.")

def __del__(self):
print("Destructor called.")

def get_a(self):
return self.a

def __getitem__(self):
print("Calling getitem() method")

def __repr__(self):
print("MyClass(1,2,3)")
return("rep method")

myobj = MyTestClass('myval')
myobj.myfunc()
#print(myobj)
#str(myobj, "Welcome", "welcome")
myobj.checkIdentifier('if')
myobj.checkIdentifier('abcd')
myobj.checkIdentifier('10')
myobj.checkIdentifier('_abcd')
print(myobj.a)
print(myobj.get_a())
print(dir(myobj))
print(myobj.get_myval())
repr(myobj)  #-->Triple1(a=1,b=2,c=3)
myobj.a
#print(myobj[a])
#print(myobj.mytest1())
#print(myobj.get_mynum())
#print(getattr(myobj, a))
#print(myobj.getattr(a))
del(myobj)

https://docs.python.org/3/contents.html

String -> length,
List -> length, sort, reverse, replace, min, max, count, index, data s
+tructure
Tuple -> type conversion
Dictionary ->
Set -> | & - ^
List Comprehension    -> range
Looping techniques -> enumerate, zip
Lambda expressions
Files and directories

Errors and Exceptions
Iterators, Generators, Decorators

Regular Expressions
Internet Access
Sending Email
XML and JSON Processing

Databases
GUI Programming
Performance Monitoring (pylint, inspect)
Testing tools (unittest)

Command line argument and options (-cmvh, sys.argv, sys.path)
Python standard library
Debugging & Misc functions

Modules and Packages
Classes and OOPS

Django Framework

Static Method & Implicit properties,
This methods are visible inside classes. It can't be accessed via obje
+cts.
class MyClass():
def __init__(self, myvar):
self.a=myvar
self.__b=2000

@property
def a(self):
return(self.__a)

@a.setter
def a(self, x):
self.__a = x
#self.a=200
"""
def myStaticMethod(a):
print("This is static method. ", a)

def myNormalMethod(self, a):
print("This is static method. ", a)

myobj = MyClass()
MyClass.myStaticMethod(200)
myobj.myNormalMethod(100)
"""
myobj=MyClass(100)
print(myobj.a)
#print(myobj.b)
myobj.a=1000
print(myobj.a)

# Implicit properties
class MyClass():
def __init__(self,x):
self.__my_attribute = x

def getAttribute(self):
return self.__my_attribute

def setAttribute(self, x):
self.__my_attribute = x

@property
def my_attribute(self):
return self.__my_attribute

@my_attribute.setter
def my_attribute(self, value):
self.__my_attribute = value

myobj = MyClass(100)
#print(myobj.__my_attribute)
print(myobj.getAttribute())
myobj.setAttribute(1000)
print(myobj.getAttribute())

myobj1 = MyClass(200)
print(myobj1.my_attribute)
myobj1.my_attribute=2000
print(myobj1.my_attribute)

REF: https://www.python-course.eu/python3_properties.php
REF: http://www.bogotobogo.com/python/python_differences_between_stati
+c_method_and_class_method_instance_method.php

Profiling,
cProfile and profile provide deterministic profiling of Python program
+s.
A profile is a set of statistics that describes how often and for how
+long various parts of the program executed.
These statistics can be formatted into reports via the pstats module.

import cProfile
import os
cProfile.run('os.getcwd()')

> python -m cProfile myscript.py
REF: https://julien.danjou.info/blog/2015/guide-to-python-profiling-cp
+rofile-concrete-case-carbonara

Struct,
This module performs conversions between Python values and C structs r
+epresented as Python bytes objects.
This can be used in handling binary data stored in files or from netwo
+rk connections, among other sources.
It uses Format Strings as compact descriptions of the layout of the C
+structs and the intended conversion to/from Python values.
mypack = struct.pack('ifiii', 10, 20.5,30,40,50)
struct.unpack('ifiii', mypack)

Queue,
import queue
myqueue = queue.Queue()  # myqueue = queue.Lifoqueue(5)
for i in range(1,10): myqueue.put(i)
print(myqueue)
print(myqueue.size())
while not myqueue.empty(): print(myqueue.get())

http://structure.usc.edu/python/dist/simple-example.html
Distributing modules,
MyModule/
mymath.py
# Math module
def add(x,y): return x + y
def sub(x,y): return x - y
def mul(x,y): return x * y

setup.py
from distutils.core import setup
setup(name="mymath",
version="1.0",
description="This is mymath module.",
author='Manojkumar R',
author_email='manoj.hispeed@gmail.com',
url='http://www.mywebsite.com/manoj',
py_modules=["mymath"])

> python setup.py sdist

Copy the tar file and extract it to some path,
mymath-1.0.tar\dist\mymath-1.0\mymath-1.0> python setup.py install --p
+refix="C:\<USER>\Desktop\MySetup"
>>> sys.path.append('C:\\<USER>\\Desktop\\MySetup\\lib\\site-packages'
+)
>>> import mymath

Regex
match, search, sub
Patterns -> ^ \$ . [abcA-E], {}, | (), +, *, ?,  \wsd, backref [phone
+, date, time]
Modifiers -> re.I, re.S

Internet Access
from urllib.request import urlopen
with urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl') as respons
+e:
#with urlopen('https://www.unixtimestamp.com/index.php') as response:
for line in response:
line = line.decode('utf-8')  # Decoding the binary data to text.
if 'EST' in line or 'EDT' in line or ' UTC' in line:  # look for
+ Eastern Time
print(line)

Sending Mail,
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

'''
server = smtplib.SMTP('smtp.gmail.com', 587)
server.starttls()

msg = "Hi,\n\nThis is test email from python program.\n\nRegards,\nMan
+oj"
server.sendmail("from", "to", msg)
server.quit()
'''

text = "Hi,\n\nThis is test email from python program.\n\nRegards,\nMa
+noj"

msg = MIMEMultipart()
msg['From'] = 'from'
msg['To'] = 'to'
msg['Subject'] = 'Test Mail [Python]'
msg.attach(MIMEText(text))

server = smtplib.SMTP('smtp.gmail.com:587')
server.ehlo()
server.starttls()
server.ehlo()
server.quit()

print "Mail Sent successfully."

Module,
""" This is my Sample module """
MYVAL=10

def myfunc():
print("This is my function")
print("Namespace: ", __name__)

if __name__ == '__main__':
print("Main Function")
print "The value of MYVAL is ", MYVAL
myfunc()

------------
import sample
#from sample import myfunc

MYVAL=100
sample.myfunc()
print("MYVAL : ", MYVAL)
print("Module MYVAL : ", sample.MYVAL)
print(sample.__doc__)

XML,
<student_collection shelf="Student Details">
<student title="Record1">
<regno>1001</regno>
<name>Ramesh</name>
<dept>CSC</dept>
</student>
<student title="Record2">
<regno>1002</regno>
<name>Suresh</name>
<dept>Mech</dept>
</student>
<student title="Record3">
<regno>1003</regno>
<name>Aakash</name>
<dept>CSC</dept>
</student>
</student_collection>

import xml.etree.ElementTree as ETree
tree = ETree.parse(r"Sample.xml")

root=tree.getroot()
#print("Collection: ", root.tag, "\nName: ", root.attrib)
print(root.tag.center(50, '*'))
print(root.attrib['shelf'])

for child in root:
print("\n", child.tag, child.attrib['title'])
print("\tRegno: ", child[0].text)
print("\tName : ", child[1].text)
print("\tDept : ", child[2].text)

JSON,
{
"id": "0001",
"dept": "CSC",
"name": "abc",
"marks": { "Maths": 98, "Science": 90, "English": 95 }
}

import json

data = {
'name' : 'ABC',
'id' : 1001,
'dept': 'CSC'
}
json_str=json.dumps(data)
print(type(json_str), json_str)
print(type(json_data), json_data)

Networking,
Server:
import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.
s.bind((host, port))        # Bind to the port

s.listen(5)                 # Now wait for client connection.
while True:
c, addr = s.accept()     # Establish connection with client.
c.send('Welcome to the Server.\nThank you for connecting...')
c.close()                # Close the connection

Client:
import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.

s.connect((host, port))
print s.recv(1024)
s.close                     # Close the socket when done

import time, os

# Define a function for the thread
def print_time( threadName, delay):
count = 0
while count < 5:
time.sleep(delay)
count += 1
print "%s: %s [%d]" % ( threadName, time.ctime(time.time()), os.
+getpid() )

# Create two threads as follows
try:
print("Program started [%d]", os.getpid())
except:
print "Error: unable to start thread"

#while 1:
time.sleep(30)
print("Processing Completed")

Forking,
import os
def child():
print('\nA new child ',  os.getpid())
os._exit(0)
while True:
newpid = os.fork()
if newpid == 0:
child()
else:
pids = (os.getpid(), newpid)
print("parent: %d, child: %d\n" % pids)
reply = input("q for quit / c for new fork")
if reply == 'c':
continue
else:
break

GUI Program,
import Tkinter
import tkMessageBox

top = Tkinter.Tk()

"""
## Message box with info message
def helloCallBack():
tkMessageBox.showinfo( "Hello Python", "Hello World")

B = Tkinter.Button(top, text ="Hello")#, command = helloCallBack)
B.pack()
"""
label = Tkinter.Message(top, text = "Welcome\n\t\tto\n python")
label.pack()

top.mainloop()

Databases,
import MySQLdb
# Open database connection
db = MySQLdb.connect("localhost", "testuser", "password", "testdb" )

# prepare a cursor object using cursor() method
cursor = db.cursor()

# execute SQL query using execute() method.
sql_query="create table student(id int, name varchar(20), dept varchar
+(20))"
#sql_query="insert into student(id, name, dept) values(1001, 'abc', 'c
+sc')"
#sql_query="insert into student(id, name, dept) values(1002, 'def', 'm
+ech')"
#sql_query="update student set dept='eee' where id=1002"
#sql_query="delete from student where id=1002"
cursor.execute(sql_query)
db.commit()

# Fetch a single row using fetchone() method.
"""
sql="select * from student"
#data = cursor.fetchone()
data_set = cursor.fetchall()
for data in data_set: print(data)
"""
db.close()

Performance,
pylint -> To check the coding standard practices in code(PEP8) and det
+ect errors.
> pip install pylint
> pylint program.py
"""welcome to python"""
import os
MYVAR = 10
print "welcome to python"
print "the value of a is: %d " %(MYVAR)
print "Name: ", os.getcwd()

Inspect -> Provides several useful functions to help get information a
+bout live objects such as modules, classes, methods, functions, trace
+backs, frame objects, and code objects.
import os
def myfunc(): print("welcome")
inspect.getdoc(os)
inspect.getfile(os)
inspect.getmodule(os)  # sys
inspect.isfunction(myfunc)
inspect.isfunction(os.getcwd)
inspect.isbuiltin(os.getcwd)

Unittest -> Framework to test/check the behaviour of functions, method
+s and classes
import unittest
myflag=False
myvar=30
return x + y

class SimpleTest(unittest.TestCase):

self.assertTrue(myvar)
self.assertFalse(myflag)

if __name__ == '__main__':
unittest.main()

Python standard library,
system, os, Date, Time, Math
import calendar
calendar.calendar(2017)
calendar.month(2017, 5)
import time
time.time(); time.gmtime(); time.sleep(5)
time.localtime(time.time()) -> [0]
time.strftime("%Y/%m/%d %H:%M:%S", time.localtime())

Debugging & Misc functions
alarm, sleep and exit
hostname and login user
Getting hostname and ip address
socket.gethostbyname(socket.gethostname())
getpass.getuser()
platform.platform(), platform.architecture(), platform.processor()

Socket functions
Executing system commands (dir|date|time \T)
Debugger
> python -m pdb sample.py

Errors and Exceptions
import sys
try:
a= 10 + 20
#raise NameError("This is raised Name Error")
except NameError as err:
print("Caught NameError Exception: ", err)
except TypeError:
print("Caught TypeError Exception: ", sys.exc_info()[1])
except:
print("Caught Other Exception: ", sys.exc_info()[1])
#sys.exit(0)
else:
print("This is else part")
finally:
print("Program completed")

Monkey patching ->
http://burnignorance.com/python-tips-and-tricks/monkey-patching-in-pyt
+hon/
https://filippo.io/instance-monkey-patching-in-python/
Monkey-patching is the technique of swapping functions or methods with
+ others in order to change a module, library or class behavior.
class MyClass():
def add(self, x, y):
return x + y
obj = MyClass()
def multiple(self, x, y):
return x * y

Function -> variable length args
def myfunc(a,b, c, d, e ):
print(a,b,c,d, e)
myfunc(10,20, [30, 40, 50], **{'d':100, 'e': 200})
myfunc(10,20, *[30, 40, 50]

Executing module as script,
sample.py
def myfunc(a,b, c, d, e ):
print(a,b,c,d, e)
myfunc(*range(50,260, 50))
if __name__ == "__main__":
myfunc(*range(10, 60, 10))

import sample  # sys.path
sample.myfunc(*range(100,600,100))

Iterators:
Iterator method is used to iterate elements from object as one by on
+e.
mylist=[10,20,30]
for i in mylist:
print i

it = iter(mylist)
it.next()   ##   In 3.x,  next(it)

Generators:
Generators are used to generate iterators. We can use yield method t
+o generate iterators. Normal function return value and yield return.
+It internally maintain refernces.
def mygenerator():
print "Welcome"
for i in (10,20):
yield i
it=iter(mygenerator())
it.next()

def mygenerator():
a= yield
yield a * 2
it=iter(mygenerator())
it.next()
it.send(20)
it.next

3.0,
def myGenerator():
for i in range(10,50, 10): yield(i)

it=myGenerator()
next(it)

Decorators:
Decorator provide a very useful method to add functionality to exist
+ing functions and classes. Decorators are functions that wrap other f
+unctions or classes.
Ex:
def math(func, x, y):
print "Math Function"
func(x,y)

print "This is addition function"
print a + b

def mul(a,b):
print "This is subtraction function"
print a * b

math(mul,10,20)

import time
def my_decorator(myfunc):
def my_wrapper():
t1 = time.time()
print("Function started ", myfunc.__name__)
myfunc()
print("Function ended ", myfunc.__name__)
t2 = time.time()
print("Time taken to execution function: ", int((t2 - t1)))

return my_wrapper

@my_decorator
def myfunc():
print("This is my function")
time.sleep(2)

myfunc()

def my_decorator(func):
def wrapper(*args, **kwargs):
print("Before call")
result = func(*args, **kwargs)
print("After call")
return result
return wrapper

@my_decorator
def add(x, y, z):
print(x, y, z)

"""
def our_decorator(func):
def function_wrapper(x):
print("Before calling " + func.__name__)
res = func(x)
print(res)
print("After calling " + func.__name__)
return function_wrapper

@our_decorator
def succ(n):
return n + 10

print(succ(100))
"""

Classes, PDF, IMAGE

Date, Time, Cal
Data Compression -> zlib, gzip
Performance Measurement -> from timeit import Timer
Testing -> unittest
Pretty print -> pprint, textwrap
Logging -> logging
Pickling and Shelving
Config Parse -> configparser
IPC and Networking -> socket, signal
GUI with Tk
Debugger -> pdb

https://docs.python.org/3/reference/index.html#reference-index
https://scipy.org/
https://www.python-course.eu/python3_namespaces.php

Exercies:
* Write a program to find the given number is odd or even number ?
Input:
Enter the number: 15
Output:
The given number(15) is odd number.

* Write a program to check whether the given string is a palindrome ?
Input:
Enter the string: racecar
Output:
The given string 'racecar' is a palindrome.

* Write a program to print the number histogram.
Input:
Enter the number for histogram: 5826
Output:
Result,
*****
********
**
******

* Write a program to count the number of characters(occurences) in a s
+tring.
Input:
Enter the string:  welcome to python program
Output:
a  ->  1
->  3
c  ->  1
e  ->  2
g  ->  1
h  ->  1
m  ->  2
l  ->  1
o  ->  4
n  ->  1
p  ->  2
r  ->  2
t  ->  2
w  ->  1
y  ->  1

=============================
Write a program to find the longest line in the given string ?
Input:
Enter the lines:
welcome to python
this is the longest line
this is my first line
this is second line
short line here
this is the end line
Output:
Given lines: [above lines here]
Longest line: this is the longest line [Length: 24]

Enhance this program to print both longest and shortest lines.

Write a program to calculate the sum of given numbers?
Input:
Enter the limit/count for numbers: 3
Enter the number 1: 10
Enter the number 2: 20
Enter the number 3: 30
Output:
The sum of given numbers [10 20 30] is:  60

Write a program to print number histogram and get the sum of all digit
+s in a number ?
Input:
Enter the number for histogram: 5826
Output:
The given number: 5826
Result,
*****
********
**
******
The sum of digits in number: 21

>>> def getNumber2(n):
global result
if n > 0:
getNumber2(n/10)
print n%10, "*" * int(n%10)
result += n%10

>>> getNumber2(mynum)
4 ****
2 **
6 ******
7 *******

def factorial(n):
if n <= 1:
return n
else:
return n * factorial(n-1)

=============================
NOTES
Joining 2 lines,
print "welcome \
to \
python"

Multiple statements in single line,
print "welcome to python"; print "second string"

Multiple assignment,
x,y = 100, 200
a=b=123

.format method,
>>> "{:15}".format(mystr)
'python         '
>>> "{:<15}".format(mystr)
'python         '
>>> "{:*<15}".format(mystr)
'python*********'
>>>
>>> "{:>15}".format(mystr)
'         python'
>>> "{:*>15}".format(mystr)
'*********python'
>>>
>>> "{:^15}".format(mystr)
'    python     '
>>> "{:*^15}".format(mystr)
'****python*****'
>>> "{:.3}".format(mystr)
'pyt'

>>> "{:d}".format(123)
'123'
>>> "{:5d}".format(123)
'  123'
>>> "{:f}".format(123.4567)
'123.456700'
>>> "{:.2f}".format(123.4567)
'123.46'
>>> "{:15.2f}".format(123.4567)
'         123.46'

Finding the max and minimum value from dictionary,
>>> mydict = {'x':500, 'y':5874, 'z': 560}
>>> max(mydict.values())
5874
>>> min(mydict.values())
500
>>> max_key = max(mydict.keys(), key=(lambda k: mydict[k]))
>>> print max_key, mydict[max_key]
y 5874
>>>
>>> min_key = min(mydict.keys(), key=(lambda k: mydict[k]))
>>> print min_key, mydict[min_key]
x 500

Built-in methods,
all()
any(), etc...

To get the content from web page,
import requests
response = requests.get("https://en.wikipedia.org/robots.txt")
print response.text

To check whether the webpage is exist,
from urllib.request import urlopen
from urllib.error import HTTPError
from urllib.error import URLError
try:
html = urlopen("http://www.example.com/")
except HTTPError as e:
print "HTTP error"
except URLError as e:
else:
print "HTML Details"

=============================

Project:
Bank ATM machine Project
Design a program to do the functionalities of Bank ATM machine.

Requirements,
- Display "Welcome Screen" with menu options
1. Account Summary
2. Withdraw Amount3. Deposit Amount
4. Mini Statement [optional]
5. Transfer Amount [optional]
6. Exit
- For any option, get the card number and pin details and do the auth
+entication [first time authentication]

- Send SMS to registered mobile number
- Send mails to registered email-id if any transaction amount is abov
+e Rs. 10000
- For 5 invalid login attempt, block the card/account

type() - get the data type for a variable
id() - get the memory address of an object
with

>>> mynum = input('Enter the number: ')
Enter the number: 10 + 20
>>> mynum
30
>>> type(mynum)
<type 'int'>
>>>
>>> mystr = input('Enter the string: ')
Enter the string: 'welcome ' + 'to Python'
>>> mystr
'welcome to Python'
>>> type(mystr)
<type 'str'>

>>> mynum = raw_input('Enter the number: ')
Enter the number: 10 + 20
>>> mynum
'10 + 20'
>>> type(mynum)
<type 'str'>
>>>
>>>
>>> mynum = eval(raw_input('Enter the number: '))
Enter the number: 10 + 20
>>> mynum
30
>>> type(mynum)
<type 'int'>

.py - Regular scripts
.py3 - (rarely used) Python3 script. Python3 scripts usually end with
+".py" not ".py3", but I have seen that a few times
.pyc - compiled script (Bytecode)
.pyo - optimized pyc file (As of Python3.5, Python will only use pyc r
+ather than pyo and pyc)
.pyw - Python script for Windows. It is executed with pythonw.exe
.pyx - Cython src to be converted to C/C++
.pyd - Python script made as a Windows DLL
.pxd - Cython script which is equivalent to a C/C++ header
.pxi - MyPy stub
.pyi - Stub file (PEP 484)
.pyz - Python script archive (PEP 441); this is a script containing co
+mpressed Python scripts (ZIP) in binary form after the standard Pytho
.pywz - Python script archive for MS-Windows (PEP 441); this is a scri
+pt containing compressed Python scripts (ZIP) in binary form after th
+e standard Python script header
.py[cod] - wildcard notation in ".gitignore" that means the file may b
+e ".pyc", ".pyo", or ".pyd".

Simple syntax
Easy/Quick to develop
Fewer lines of code
Reduce development time
Dynamic data type allocation

Introduction - Collegue, Any doubt stop,
OS and Intro -

As of 03/10/2017, (Rent Rs. 8700/2 -> 4350)
EB bill: Rs. 265
Total: Rs. 265  => Rs. 132
For FSaravana,
Remaining + 2 months rent + others
Rs. 34538 + Rs. 4350 + Rs. 132 => Rs. 39020

As of 03/11/2017, (Rent Rs. 4300/2 -> 2150)
For Saravana,
Remaining + 1 month rent + others
Rs. 34020 + Rs. 2150 + Rs. 0 => Rs. 36170

Rent/Owner Account,
Bank Name:  INDIAN OVERSEAS BANK
IFSC Code:  IOBA0000098
Account Number:  009801000046497

Electricity Bill,
Consumer No: 092370211213
Name: A.MOHAMEDALI KAMARUNISSA
Region: 09-Chennai-South
Circle: 400-South1

We need to get the remaining EB amount (Rs. 170) from neighbor for pre
+vious bills.

EB Bill,
07/07,
Total: 380 Units -> Rs. 770 (Per Unit Rs. 2.02)
Ours : 180 Units -> Rs. 365
Rem  : 200 Units -> Rs. 405

08/09,
Total: 300 Units -> Rs. 530 (Per Unit Rs. 1.76)
Ours : 150 Units -> Rs. 265
Rem  : 150 Units -> Rs. 265

For them, Rs. 670 (last 4 months)
https://tamil.boldsky.com/home-garden/how-to/2017/did-you-know-what-sh
+ould-not-kept-fridge-017611.html
https://curl.trillworks.com/
```import sys, os, time
import logging
import psutil

pid_file = 'test.PID'
block_file = 'test.BLOCKED'

def createPidFile(filename):
mypid = os.getpid()
print("Current process ID: {0}".format(mypid))
fp = open(pid_file, 'w')
fp.write(str(mypid))
fp.close()

def checkFileExist(filename):
if os.path.isfile(filename):
print("File [{0}] is exist." .format(filename))
return True
print("File [{0}] does not exist." .format(filename))
return False

fp = open(filename, 'r')
print('PID: {0}' .format(int(data)))
return int(data)

def checkRunning():
if checkFileExist(pid_file):
if checkPidExist(pid):
print("Process is already running...")
sys.exit(0)
else:
createPidFile(pid_file)
print("PID file created successfully...")
else:
print("Process is not running.")

def checkPidExist(pid):
if psutil.pid_exists(pid):
print("PID [{0}] is running." .format(pid))
return True
print("PID [{0}]does not exist." .format(pid))

checkRunning()

skip_day = '17,18,20'
run_week  = 'Mon,Tue,Wed,Thu,Fri'
start_time = '17:30'
end_time   = '19:20'

def checkRunTime():
(week_day, day, hour, min) = time.strftime('%a:%d:%H:%M', time.local
+time()).split(':')
(hour, min) = (int(hour), int(min))
print("Current Day and Time:  {0} {1} - {2}:{3}" .format(day, week_d
+ay, hour, min))

if skip_day:
skip_days = skip_day.split(',')
print('Skip Days: ',skip_days)
if day in skip_days:
return False

run_weeks = run_week.split(',')
(start_hr, start_min) = [int(x) for x in start_time.split(':')]
(end_hr, end_min)     = [int(x) for x in end_time.split(':')]
print('Run Days : ',run_weeks)
print('Run Time :  {0}:{1} - {2}:{3}' .format(start_hr, start_min, e
+nd_hr, end_min))

#print(day, run_weeks, hour, start_hr, end_hr,  min, start_min, end_
+min)
if (week_day in run_weeks) and (hour >= start_hr and hour <= end_hr)
+:
if ((hour == start_hr and min < start_min) or (hour == end_hr and
+min > end_min)):
return False
return True
return False

if not checkRunTime():
print("Runtime does not match for current run...")
sys.exit(0)

print("Runtime matched for current run...")
while True:
if checkFileExist(block_file):
print('BLOCK file exist.')
time.sleep(2)
continue
print("Inside Loop [{0}]" .format(os.getpid()))
time.sleep(5)
```a=500

# Simple function
def myfunc():
#global a
#a=100
print "This is myfunc() function."
#print "The value of a is ", a

# Function with args
print "Going to add two numbers: ", a, b
return a + b

# Function with default args
print "Going to add two numbers: ", a, b
return a + b

# Function with variable length args
def myfunc1(a,b,c):
print "Calling myfunc1()"
print a,b,c

# Function with variable length args
def myfunc2(**a):
print "Calling myfunc2()"
print a

#myfunc()

mylist=[10,20,30]
#myfunc1(*mylist)
mydict={'a': 100, 'b': 200, 'c': 300}
#myfunc1(**mydict)

#myfunc2(mylist)

=====================================================
OS,
Interface between hardware and user.
Basic need is to do read/write operation on HW. (storage processing)

Memory management - Main memory / virtual memory
Process management - processor, processes, threads, cpu scheduling, p
+rocess synchronize, dead locks, etc.
File management - file/folder directory structure.
Device management - attach/detach device, plug-play
Security - User / Group permission, patches
Disk Management
System performance

Layers,
User1, User2
Software -> OS -> System software, Application software
HW -> CPU, RAM, IO

Diff types of OS:
Windows
Unix / Linux (RHEL, Solaris, Debian, Ubuntu, HP-UX, AIX)
Mac / ios
Andriod

Diagram, (unix)
HW -> Kernel ->  Shell -> Apps, Compiler, Commands, etc

Boot Process
BIOS
Boot loader (GRUB / LILO)
Kernel
Operating System
Process (init)

Diff Languages ???
Why Python ?
1985 - 1990 -> Guido van Rossum
Open source -> GPL License (high level programming language)
Interpreted language (Compiled vs Interpreted), PVM

Who Uses??
Google -> web search
Youtue -> Video sharing
Dropox
bittorrent
NSA -> National Search Agency
NASA -> Scienttific program
irobot
Company -> intel, cisco, HP, Ibm, seagate and etc

What can we do?
System programming -> automation, report generation, monitoring, etc
GUI
Web programming
Network / Internet Programming
Component Integration
Database Programming
Numeric & Scientific Program
Gaming & Robotic
Data Mining / Analytics & Data science

-----------------------------------------------
import sys, os, time, re
import xlrd
import logging
import MySQLdb

filename = '/home/manoj/TechTrend/Dashboard.xls'
(db_connect, db_cursor) = ('', '')
dashboardDetail = [
{'name': 'Higher Volumes', 'table': 'higher_volumes', 'range': [(2, 1)
+, (22, 5)],
'columns': ('ttq_daily', 'symbol', 'ltp', 'perc_chg', 'mn_ttq_perc')}
#{'name': '15 Curr Volume Breakers', 'table': 'curr_volume_breakers',
+'range': [(26, 1), (46, 6)]},
#{'name': 'SIGNALS IN MOMENTUM STOCKS', 'table': 'signals_in_momentum_
+stocks', 'range': [(51, 1), (71, 6)]},
#{'name': 'NEAR MONTH HIGH', 'table': 'near_month_high', 'range': [(76
+, 1), (90, 3)]},
#{'name': 'NEAR MONTH LOW', 'table': 'near_month_low', 'range': [(76,
+5), (90, 7)]},
#{'name': 'GAINERS OF THE DAY', 'table': 'gainers_of_day', 'range': [(
+96, 0), (110, 4)]},
#{'name': 'LOOSERS OF THE DAY', 'table': 'losers_of_day', 'range': [(9
+6, 6), (110, 9)]},
#{'name': 'MONTHLY VOLUMES', 'table': 'monthly_volumes', 'range': [(11
+6, 1), (164, 4)]},
#{'name': 'MONTHLY GAINERS', 'table': 'monthly_gainers', 'range': [(11
+6, 6), (141, 9)]},
#{'name': 'MONTHLY LOOSERS', 'table': 'monthly_losers', 'range': [(145
+, 6), (164, 9)]}
]

def main():
checkFileExist(filename)
openDbConnection()
processExcelData()
sys.exit(0)

def processExcelData():
global db_connect, db_cursor
try:
workbook = xlrd.open_workbook(filename)
print "No of sheets in workbook", workbook.nsheets
worksheet = workbook.sheet_by_index(0)
print "Total No. of rows: ", worksheet.nrows
for dashboard in dashboardDetail:
table = dashboard['table']
print "\nName: ", dashboard['name']
print "Table: ", table
print "Range: ", dashboard['range']
(srow, scol) = (dashboard['range'][0][0], dashboard['range'][0][
+1])
(erow, ecol) = (dashboard['range'][1][0], dashboard['range'][1][
+1])

query="insert into %s(%s) values " %(table, ', '.join(dashboard[
+'columns']))
print "QUERY: ", query
for i in range(srow, erow):
#print "\nROW [%d] : " %(i),
k=0
query += '('
for j in range(scol-1, ecol):
value = worksheet.cell(i, j).value
query += "'{0}'," .format(value)
query = re.sub(',\$', '), ', query)
query = re.sub(', \$', '', query)
print "QUERY: ", query

last_updated_time = executeQuery("select max(created_time) from
+%s where active='Y'" %(table), True)
update_query = "update %s set active='N' where active = 'Y' and
+created_time <= '%s'" %(table, last_updated_time)
print "QUERY: ", update_query
executeQuery(update_query)
executeQuery(query)
#print "[HEADER] -> ", worksheet.row_values(0)
#for row in range(1, worksheet.nrows):
#  print "[DATA] -> ", worksheet.row_values(row)

except:
print "Exception caught", sys.exc_info()[1]
db_connect.commit()
db_connect.close()
print "Database connection closed successfully."

def executeQuery(query, Return=False):
global db_connect, db_cursor
print "Query: ", query
#return
try:
db_cursor.execute(query)
if Return:
data = db_cursor.fetchone()
print "DATA: ", data
return data[0]
except:
print "Exception caught.", sys.exc_info()[1]

def openDbConnection():
global db_connect, db_cursor
try:
db_connect = MySQLdb.connect("trendz.com","trend_d","dat17","trend
+_d" )  ## CHANGE MYSQL ##
print "Database connection established successfully."
db_cursor = db_connect.cursor()
print "Cursor object created successfully."
except:
print "Unable to establish connection with database. Error: ", sys
+.exc_info()[1]
sys.exit(0)

## To check the existence of file
def checkFileExist(filename):
if not os.path.isfile(filename):
print "File does not exist. [%s]" %(filename)
sys.exit(0)

main()

---------------------------------
def running_count(iterable,p):
match_count = 0
it = iter(iterable)
while True:
try:
if p(next(it)):
match_count += 1
yield(match_count)
except StopIteration:
return

def stop_when(iterable,p):
it = iter(iterable)
while True:
try:
myval = next(it)
if p(myval):
return
yield(myval)
except StopIteration:
return

def yield_and_skip(iterable):
it = iter(iterable)
while True:
try:
myval = next(it)
if str(myval).isdigit():
[next(it) for i in range(myval)]
yield(myval)
except StopIteration:
return

def windows(iterable,m,n=1):
it = iter(iterable)
tmplist = []
while True:
try:
if len(tmplist) > 0:  tmplist = tmplist[n:m]
tmplist.extend([next(it) for i in range(len(tmplist), m)])
yield(tmplist)
except StopIteration:
return

def alternate(*iterables):
iterables = [iter(it) for it in iterables]
while True:
for it in iterables:
try:
yield(next(it))
except StopIteration:
return

def myzip(*iterables):
iterables = [iter(it) for it in iterables]
while True:
tmplist = []
for it in iterables:
try:
tmplist.append(next(it))
except StopIteration:
tmplist.append(None)
if all(v is None for v in tmplist): return
yield(tmplist)

class Backwardable:
def __init__(self,iterable):
self._iterable = iterable

def __iter__(self):
class B_iter:
def __init__(self,iterable):
self._all      = []
self._iterator = iter(iterable)
self._index    = -1 # index of just returned value fro
+m __next__ or __prev__

def __str__(self):
return '_all={}, _index={}'.format(self._all,self._ind
+ex)

def __next__(self):
if len(self._all) == 0:
while True:
try:
self._all.append(next(self._iterator))
except:
break
'''
if len(self._all) == self._index +1:
try:
self._index +=1
self._all.append(next(self._iterator))
except :
self._index-=1
raise
else:
self._index+=1
return self._all[self._index]
'''
if self._index < len(self._all) -1 :
self._index += 1
return self._all[self._index]
raise(StopIteration("Stop the iteration. No more next
+values !!"))

def __prev__(self):
#print(self._index)
if self._index <= 0:
raise(AssertionError("Assertion error caught. No m
+ore previous values !!"))
self._index -= 1
return self._all[self._index]

'''
self._index -=1
try:
assert self._index> -1, 'No more previous value.'
except AssertionError:
self._index+=1
raise
return self._all[self._index]
'''
return B_iter(self._iterable)

def prev(x): return x.__prev__()

if __name__ == '__main__':
# Test running_count; you can add your own test cases
print('\nTesting running_count')
for i in running_count('bananastand',lambda x : x in 'aeiou'): # i
+s vowel
print(i,end=' ')
print()

for i in running_count(hide('bananastand'),lambda x : x in 'aeiou'
+): # is vowel
print(i,end=' ')
print()

print(nth(running_count(primes(),lambda x : x%10 == 3),1000))

# Test stop_when; you can add your own test cases
print('\nTesting stop_when')
for c in stop_when('abcdefghijk', lambda x : x >='d'):
print(c,end='')
print()

for c in stop_when(hide('abcdefghijk'), lambda x : x >='d'):
print(c,end='')
print('\n')

print(nth(stop_when(primes(),lambda x : x > 100000),100))

# Test group_when; you can add your own test cases
print('\nTesting yield_and_skip')
for i in yield_and_skip([1, 2, 1, 3, 'a', 'b', 2, 5, 'c', 1, 2, 3,
+ 8, 'x', 'y', 'z', 2]):
print(i,end=' ')
print()

for i in yield_and_skip(hide([1, 2, 1, 3, 'a', 'b', 2, 5, 'c', 1,
+2, 3, 8, 'x', 'y', 'z', 2])):
print(i,end=' ')
print()

print(nth(yield_and_skip(primes()),5))

# Test windows; you can add your own test cases
print('\nTesting windows')
for i in windows('abcdefghijk',4,2):
print(i,end=' ')
print()

print('\nTesting windows on hidden')
for i in windows(hide('abcdefghijk'),3,2):
print(i,end=' ')
print()
print(nth(windows(primes(),10,5),20))

# Test alternate; add your own test cases
print('\nTesting alternate')
for i in alternate('abcde','fg','hijk'):
print(i,end='')
print()

for i in alternate(hide('abcde'), hide('fg'),hide('hijk')):
print(i,end='')
print()

for i in alternate(primes(20), hide('fghi'),hide('jk')):
print(i,end='')
print()
print(nth(alternate(primes(),primes()),50))

# Test myzip; add your own test cases
print('\nTesting myzip')
for i in myzip('abcde','fg','hijk'):
print(i,end='')
print()

for i in myzip(hide('abcde'), hide('fg'),hide('hijk')):
print(i,end='')
print()

for i in myzip(primes(20), hide('fghi'),hide('jk')):
print(i,end='')
print('\n')
print(nth(myzip(primes(),primes()),50))

# Test Backwardable; add your own test cases
print('\nTesting Backwardable')
s = 'abcde'
i = iter(Backwardable(s))
print(i)
print(next(i),i) #a
print(next(i),i) #b
print(next(i),i) #c
print(prev(i),i) #b
print(prev(i),i) #a
try:
print(prev(i),i)
except AssertionError:
print('Tried to prev before first value')
print(next(i),i) #b
print(next(i),i) #c
print(next(i),i) #d
print(next(i),i) #d
try:
print(next(i),i)
except StopIteration:
print('Correctly raised StopIteration')

------------------------------------

Python Pandas and Numpy,
https://www.hackerearth.com/practice/machine-learning/data-manipulatio
+n-visualisation-r-python/tutorial-data-manipulation-numpy-pandas-pyth
+on/tutorial/

IOT,
https://www.element14.com/community/groups/internet-of-things/blog/201
+7/02/17/iot-with-python-essential-packages

sdcard,
http://www.toontricks.com/2017/07/ubuntu-changes-to-sd-card-undone-aft
+er.html
https://superuser.com/questions/795034/format-a-protected-corrupted-sd
+-card
+-re-mount-e-g-deleted-files-re-appear

Thanks for the reply.

2017-09-16 Athanasius changed <pre> to <code> tags, etc.

-- The wisest mind has something yet to learn.

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