Python reads incremental text

Question

I saw a piece of code, as follows：

with open(‘text.txt’,‘r’)as fp:
  
    while True:
        data_line=fp.readline()

        if data_line:
            print(data_line)

writing data in txt，and all the time python will keep outputting.

I think this code is great. But I don't quite understand the line if data_line:

I hope someone can explain it, thanks.

Does this answer your question? [What is Truthy and Falsy? How is it different from True and False?](https://stackoverflow.com/questions/39983695/what-is-truthy-and-falsy-how-is-it-different-from-true-and-false) — Pranav Hosangadi, Jun 22 '21 at 17:27

score 1 · Answer 1 · answered Jun 22 '21 at 17:28

1

if data_line checks if any text was read: if it is an empty string it will skip that section (the print(data_line))

answered Jun 22 '21 at 17:28

n4321d

Debashis Dip · Accepted Answer · 2021-06-22T17:43:38.707

1

Basically the code is checking if there is any value in the variable data_line and printing the value if the value is not '' empty string.

edited Jun 22 '21 at 17:43

answered Jun 22 '21 at 17:31

Debashis Dip

1

I've never seen `fp.readline()` returning `None`. It may return an empty string though. – Jun 22 '21 at 17:38
Thanks, You were correct. Fixed the answer. – Debashis Dip Jun 22 '21 at 17:44

2 Answers2