readline() method does not work properly in my code

September 27, 2023

I have been working on decode problem.
I think that my function named decode works properly.(whole codes below)
However, I do not think readline() method does not work properly.
Where should I put print(decode(line)) line??

Whole code:

import matplotlib.pyplot as plt
import pandas as pd

def decode(encoded_str):
    decoded_str = ''
    for char in encoded_str:

        decoded_str += chr(ord(char)-1)
    return decoded_str

print(decode('Hp Jsjti')) #print Go Irish

f=open('data/secret_message.txt','r')
# read and process the file one line at a time 
while True:
    line = f.readline()

    if line =='':
        break
print(decode(line))
f.close()

I tried to replace the line some times, but it did not show up anythig.

>Solution :

You are printing the line variable outside the while loop so it will return undefined and will not print anything.

Consider printing line variable within while loop:

while True:
    line = f.readline()
    print(decode(line)) # Decoding each line after reading it

    if line === '': # Also consider `===` instead of `==` read more here: https://stackoverflow.com/questions/359494/which-equals-operator-vs-should-be-used-in-javascript-comparisons
        break

Hope this helps!