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What is the difference between '/' and '//' when used for division?
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In Python 3.x, 5 / 2 will return 2.5 and 5 // 2 will return 2. The former is floating point division, and the latter is floor division, sometimes also called integer division.
In Python 2.2 or later in the 2.x line, there is no difference for integers unless you perform a from __future__ im...
Purpose of Python's __repr__
...e to create this object. See official documentation here. __repr__ is more for developers while __str__ is for end users.
A simple example:
>>> class Point:
... def __init__(self, x, y):
... self.x, self.y = x, y
... def __repr__(self):
... return 'Point(x=%s, y=%s)' % (self.x...
What is a None value?
...dying Python, and I read a chapter which describes the None value, but unfortunately this book isn't very clear at some points. I thought that I would find the answer to my question, if I share it there.
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Is there a way to 'uniq' by column?
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sort -u -t, -k1,1 file
-u for unique
-t, so comma is the delimiter
-k1,1 for the key field 1
Test result:
overflow@domain2.com,2009-11-27 00:58:29.793000000,xx3.net,255.255.255.0
stack2@domain.com,2009-11-27 01:05:47.893000000,xx2.net,127.0.0.1
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What is the difference between g++ and gcc?
...t is the difference between g++ and gcc? Which one of them should be used for general c++ development?
10 Answers
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How do I find out what keystore my JVM is using?
...RE -->lib---> security--> cacerts" Note the "s" at the end, just for any future readers.
– Keir Nellyer
Jul 27 '14 at 19:15
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MD5 algorithm in Objective-C
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md5 is available on the iPhone and can be added as an addition for ie NSString and NSData like below.
MyAdditions.h
@interface NSString (MyAdditions)
- (NSString *)md5;
@end
@interface NSData (MyAdditions)
- (NSString*)md5;
@end
MyAdditions.m
#import "MyAdditions.h"
#import <Com...
How to limit the maximum value of a numeric field in a Django model?
Django has various numeric fields available for use in models, e.g. DecimalField and PositiveIntegerField . Although the former can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a ...
Converting between datetime, Timestamp and datetime64
...t;>> numpy.__version__
'1.8.0.dev-7b75899'
It returns long because for numpy.datetime64 type .astype(datetime) is equivalent to .astype(object) that returns Python integer (long) on numpy-1.8.
To get datetime object you could:
>>> dt64.dtype
dtype('<M8[ns]')
>>> ns = ...
Does reading an entire file leave the file handle open?
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For a while, there weren't really other Python implementations; but relying on implementation details is not really Pythonic.
– Karl Knechtel
Sep 14 '11 at 0:00
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