How to print a string with a certain value from a file in python?

Question

Python

Let's say I have a file called 'file.txt'
The lines are written in it:
123456
654321
41444
2423425
255325
How can I find and display the line with the value 654321 if I don't know the number of the line.

Answer 1

If you want to display the line 654321 (you wrote exactly that) But if your task is to "find the line number with the text 654321", then the solution will be different. And if your task is to read data and write new data instead, then it is wiser to use ready-made solutions - json + dict (for simply storing a small number of infrequently changed key-value pairs) or a database (if there is a lot of data, stability and failure resistance are important)
print("654321")

Answer 2

More or less like this

word=input('Текст:')
i=0
with open('file.txt') as file:
    for line in file:
        i=i+1
        if word in line:
            print( line,'Номер строки:', i,end='')
            break