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
def add(a,b):
  print "Going to add two numbers: ", a, b
  return a + b

# Function with default args
def add1(a, b=50):
  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()

#add(10,20)
#add(b=200, a=100)

#add1(100)
#add1(1000,2000)

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)
 
Tasks,
 Memory management - Main memory / virtual memory
 Process management - processor, processes, threads, cpu scheduling, process 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
 MBR (boot loader)
 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)
 Latest version -> 2.7.13, 3.6.2
 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': [(96, 6), (110, 9)]},
#{'name': 'MONTHLY VOLUMES', 'table': 'monthly_volumes', 'range': [(116, 1), (164, 4)]},
#{'name': 'MONTHLY GAINERS', 'table': 'monthly_gainers', 'range': [(116, 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 from __next__ or __prev__
        
            def __str__(self):
                return '_all={}, _index={}'.format(self._all,self._index)
        
            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 more 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'): # is 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-manipulation-visualisation-r-python/tutorial-data-manipulation-numpy-pandas-python/tutorial/

IOT,
https://www.element14.com/community/groups/internet-of-things/blog/2017/02/17/iot-with-python-essential-packages

sdcard,
http://www.toontricks.com/2017/07/ubuntu-changes-to-sd-card-undone-after.html
https://superuser.com/questions/795034/format-a-protected-corrupted-sd-card
https://ubuntuforums.org/showthread.php?t=1985599
https://askubuntu.com/questions/262892/changes-to-sd-card-undone-after-re-mount-e-g-deleted-files-re-appear