scanf in python

AMD amdescombes at
Mon Jul 21 18:50:29 CEST 2008


I often need to parse strings which contain a mix of characters, 
integers and floats, the C-language scanf function is very practical for 
this purpose.
I've been looking for such a feature and I have been quite surprised to 
find that it has been discussed as far back as 2001 but never 
implemented. The recommended approach seems to be to use split and then 
atoi or atof or to use regex and then atoi and atof. Both approaches 
seem to be a lot less natural and much more cumbersome than scanf. If 
python already has a % string operator that behaves like printf, why not 
implement either a %% or << string operator to behave like scanf, use 
could be like the followng:

a, b, c = "%d %f %5c" %% "1 2.0 abcde"


a, b, c = "%d %f %5c" << "1 2.0 abcde"

%% is closer to the % operator

<< seems more intuitive to me

either of this methods seems to me much simpler than:

lst = "1 2;0 abcde".split()
a = int(lst[0])
b = float(lst[1])
c = lst[2]

or even worse when using regular expressions to parse such simple input.

I like python because it is concise and easy to read and I really think 
it could use such an operator.

I know this has been discussed before and many times, but all previous 
threads I found seem to be dead and I would like to invite further 
investigation of this topic.


André M. Descombes

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