Re-read an open file Python

I have a script that reads a file and then completes tests based on that file however I am running into a problem because the file reloads after one hour and I cannot get the script to re-read the file after or at that point in time.

So:

• GETS NEW FILE TO READ
• Reads file
• performs tests on file
• GET NEW FILE TO READ (with same name – but that can change if it is part of a solution)
• Reads new file
• perform same tests on new file

Can anyone suggest a way to get Python to re-read the file?

Answers:

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Method 1

Either seek to the beginning of the file

with open(...) as fin:
    fin.read()   # read first time
    fin.seek(0)  # offset of 0
    fin.read()   # read again

or open the file again (I’d prefer this way since you are otherwise keeping the file open for an hour doing nothing between passes)

with open(...) as fin:
    fin.read()   # read first time

with open(...) as fin:
    fin.read()   # read again

Putting this together

while True:
    with open(...) as fin:
        for line in fin:
            # do something 
    time.sleep(3600)

Method 2

You can move the cursor to the beginning of the file the following way:

file.seek(0)

Then you can successfully read it.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0