file.readlines( ) question

[vch]

Does a call to file.readlines( ) reads all lines at once in the memory?
Are the any reasons, from the performance point of view, to prefer
*while* loop with readline() to *for* loop with readlines()?

[Erik Max Francis]

vch wrote:

Does a call to file.readlines( ) reads all lines at once in the memory?
Are the any reasons, from the performance point of view, to prefer
*while* loop with readline() to *for* loop with readlines()?

Yes, and you just mentioned it. .readlines reads the entire file into
memory at once, which can obviously be expensive if the file is large.

A for loop with .readline, of course, will work, but modern versions of
Python allow iteration over a file, which will read it line by line:

for line in aFile:
...

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Erik Max Francis && ma*@alcyone.com && http://www.alcyone.com/max/
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[vch]

Erik Max Francis wrote:

... modern versions of
Python allow iteration over a file, which will read it line by line:

for line in aFile:
...

Thanks! Just what I need.