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python - Why the second time I run "readlines" on the same file nothing is returned?

>>> f = open('/tmp/version.txt', 'r')
>>> f
<open file '/tmp/version.txt', mode 'r' at 0xb788e2e0>
>>> f.readlines()
['2.3.4
']
>>> f.readlines()
[]
>>>

I've tried this in Python's interpreter. Why does this happen?

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You need to seek to the beginning of the file. Use f.seek(0) to return to the begining:

>>> f = open('/tmp/version.txt', 'r')
>>> f
<open file '/tmp/version.txt', mode 'r' at 0xb788e2e0>
>>> f.readlines()
['2.3.4
']
>>> f.seek(0)
>>> f.readlines()
['2.3.4
']
>>>

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