COMMAND LINE PROGRAMS IN PYTHON:



This page has pograms which you can use as command line tools.

1) arrlen.py:



This program is used to print the length of each line in a file.

CODE:

  from sys import stdin
  standardin = stdin.readlines()
  #print standardin
  
  for i in range (0,len(standardin)) :
      count =0
      for j in standardin[i]:
          if j not in "\n\r": count += 1
      print str(count)+" " +standardin[i].replace("\n","").replace("\r","")
USE : echo test.txt | python arrlen.py

OUTPUT:
5 hello
6 there,
7 namaste


2) cat.py



This is used to print the the content of a file

CODE:

  import sys
  
  filenames= sys.argv[1:]
  #print filenames
  all_lines = []
  
  for i in range (0,len(filenames)):
      f = open(filenames[i], "r")
      all_lines.extend(f.readlines())
      f.close()
  
  
  for i in all_lines:
      print i.rstrip()

USE:python cat.py test.txt

OUTPUT:
hello
there,
namaste

3) stcount.py


This program is used count the frequency of a particular word in a string or file.

CODE


  from sys import stdin
  import sys
  

  standardin = stdin.readlines()

  all_lines = ''
  for i in standardin:
      all_lines += i.replace('\n','').replace('\r','')
  

  word= sys.argv[1:][0]
  

  n =len(all_lines.split(word))-1
  print n
USE : echo "hello\nworld" | python stcount.py e
"e" is the word you want to count here 
              *OR*
    echo test.txt | python stcount.py e
OUTPUT :
1


4) sort.py


This program is used to sort according to the length of a string

CODE


  from sys import stdin
  standardin = stdin.readlines()
  
  parts=[]
  
  for i in standardin:
      i = i.replace("\n","").replace("\r","")
      parts.append ( (int(i.split(" ")[0]), i ) )
  
  parts = sorted(parts)
  #print parts
  
  for i in parts:
      print i[1]
USE: cat test.txt | python arrlen.py | sort.py

OUTPUT:
11 hello world
12 this is test
17 how are you doing