Getting Started With Raspberry Pi, 4th Edition

Here’s another example (

ReadFile.py

) that reads in a file name as an

argument from the command line (run it from the shell with python3

ReadFile.py lename). The program opens the file, reads each line

as a string, and prints it. Note that print() acts like println() does

in other languages; it adds a new line to the string that is printed.

The end argument to print() suppresses the new line:

# Open and read a le from command-line argument

import sys

if (len(sys.argv) != 2):

print("Usage: python3 ReadFile.py lename")

sys.exit()

scriptname = sys.argv[0]

lename = sys.argv[1]

le = open(lename, "r")

lines = le.readlines()

le.close()

for line in lines:

print(line,end = '')

Even More Modules

One of the reasons Python is so popular is that there ...