How do I read each line of a file and add if statements?

Question

I’m pretty new to Python, but I’m trying to learn. One idea I had for a simple script was to have a script that reads and writes to a log file during execution. Then based on what’s in that log file, helps dictate what the script does the next time it’s ran.

Reading and writing to a file seems simple enough in Python,

f = open('textfile.txt', 'r+')

Reading and print out each line of a file seems simple too,

for line in f:
    print line
    line=f.next()
    print line

But, how do I incorporate an IF statement when reading a file to do something based on what was read?

for line in f
    if line == '1':
       print "Works!"
    else:
       print line
    line=f.next()
    print line
f.close()

Output

Asked By: Fastidious

||

Source

Answer 1

The problem is that line is equal to

'1n'

You first need to remove the newline character by doing first in your loop:

line = line.rstrip()

Another possibility could be, in this particular case in which you expect integers, to cast the line string into an integer, and then to compare to an integer:

line = int(line)
if line == 1:
    # and so on

Answered By: Colin Bernet

How do I read each line of a file and add if statements?

Question:

Answers: