Python - Preventing closing a file after printing its content

Question

I want to read a file with python, print its contents first, and then do my operations on its data.

Here is my code:

with open("myFile.txt", 'rw') as inputFile:
    print(inputFile.read())
    for i,j in enumerate(pdbFile):
        do whatever
        count the lines 
print("Number of lines", numberOflines)

The output in this case is numberOfLines = 0.

However, if I comment the command print(pdbFile.read()), it gives me the correct number of lines. So apparently the file is being closed after reading the file.

How to force python to keep the file open until I finish my calculations?

No, the file is not closed. You just can't read a file more than once without rewinding to the start. — Martijn Pieters, Aug 12 '18 at 08:49
Add `pdbFile.seek(0)` or read once into a variable, then print the variable and loop over the `.splitlines(True)` result. — Martijn Pieters, Aug 12 '18 at 08:50

score 1 · Accepted Answer · edited Aug 12 '18 at 09:56

1

After you read() the file, you reached the end of it, and though your file is still open, there is no line left to iterate on.

So, either:

Don't read it before your for loop, or;
Go back to the start of the file after reading it with seek(0), or;
Close it and open it again.

edited Aug 12 '18 at 09:56

N Chauhan

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answered Aug 12 '18 at 08:50

Thierry Lathuille

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Python - Preventing closing a file after printing its content

1 Answers1