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PyPro #32 Emulating the 'head' command of Unix

Posted on by lakshayarora7
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Emulating the 'head' command of Unix in Python

Emulating the 'head' command of Unix in Python

Emulating the 'head' command of Unix in Python: In Unix, the head -n fileName command displays the first n lines of the file fileName. Write a program in Python to emulate the same functionality.

Emulating the 'head' command of Unix in Python

# Ask the user for the filename whose head is to be displayed, and the number of lines comprising the head.
# Output the first whatever-the-input lines.
 
fileName = input('Please enter the name of the file you wish view the head of: ')
numberOfLines = int(input('Please enter the number of lines in the head that you wish to view: '))
  
fileHandler = open( fileName, 'r' )
  
# list to store the head
lines = []
  
# using a while loop and readline() function, read only a fixed number of lines and append to above list
while len(lines) < numberOfLines:
    lines.append(fileHandler.readline())
  
fileHandler.close()
  
# Some text to replicate Unix command syntax.
print('\nExecuting command: head -' + str(numberOfLines) + " " + fileName + "\n")
  
# displaying the head
for line in lines:
    print(line, end="")
Try it here.

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