About open file for Read

Steven D'Aprano steve+comp.lang.python at pearwood.info
Mon Dec 10 21:45:39 CET 2012


On Mon, 10 Dec 2012 08:36:22 -0800, moonhkt wrote:

> Hi All
> 
> I am new in Python. When using open and then for line in f .
> 
> Does it read all the data into f object ? or read line by line ?

Have you read the Fine Manual?

http://docs.python.org/2/library/stdtypes.html#file-objects

If you have read it, and the answer is still not clear, then please tell 
us so we can improve the documentation.

`for line in open(file, "r"):` does not read the entire file into memory 
at once, it iterates over the file reading one line at a time.


-- 
Steven



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