Read input from redirected stdin with python

Question

I have this loop that reads lines from stdin until a newline is entered, however, this only works from typing in the input. How do I get the program to read lines from a redirec

Answer 1

Consider the following option

import sys
sys.stdin = open("input.txt", "r")

Answer 2

As others have mentioned, probably your condition line == '\n' never holds true. The proper solution would be to use a loop like:

for line in sys.stdin:
  stripped = line.strip()
  if not stripped: break
  lines.append(stripped)

Answer 3

ETA: Based on your comment that you're running into an infinite loop, you probably just don't have an empty line at the end of the file.

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Use a pipe character:

input.input | python graph.py

If input.input is in fact a file rather than a stream, use cat to create a stream from it:

cat input.input | python graph.py