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Access an arbitrary element in a dictionary in Python
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for a non-destructive popitem you can make a (shallow) copy: key, value = dict(d).popitem()
– Pelle
Jan 31 '18 at 10:35
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How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
How to increase the vertical split window size in Vim
:vsplit (short form: :vs ) split the Vim viewport vertically. :30vs splits the viewport, making the new window 30 characters wide. Once this 30 char window is created, how would one change it's size to 31 or 29?
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Two way/reverse map [duplicate]
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1
>>> del d['foo']
>>> d['bar']
Traceback (most recent call last):
File "<stdin>", line 7, in <module>
KeyError: 'bar'
I'm sure I didn't cover all the cases, but that should get you started.
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Image Greyscale with CSS & re-color on mouse-over?
...rayscale(100%);
/* Chrome 19+ & Safari 6+ */
-webkit-transition: all .6s ease;
/* Fade to color for Chrome and Safari */
-webkit-backface-visibility: hidden;
/* Fix for transition flickering */
}
img.grayscale:hover {
filter: none;
-webkit-filter: grayscale(0%);
}
sv...
Finding the index of elements based on a condition using python list comprehension
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In Python, you wouldn't use indexes for this at all, but just deal with the values—[value for value in a if value > 2]. Usually dealing with indexes means you're not doing something the best way.
If you do need an API similar to Matlab's, you would use numpy, a packag...
Adding a cross-reference to a subheading or anchor in another page
... because it works across files, when section headings are changed, and for all builders that support cross-references.
RST, in General
The tools that convert RST files to HTML do not necessarily have a notion of collection. This is the case for instance if you rely on github to convert RST files ...
Submitting a multidimensional array via POST with php
...u would read the previous input name after cloning, and increment by 1 manually for each input name attribute in the clone.
– Daniel
Nov 18 '18 at 0:04
add a comment
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Python 2.7: Print to File
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In Python 3.0+, print is a function, which you'd call with print(...). In earlier version, print is a statement, which you'd make with print ....
To print to a file in Python earlier than 3.0, you'd do:
print >> f, 'what ever %d', i
The >> operator directs pr...
open read and close a file in 1 line of code
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You don't really have to close it - Python will do it automatically either during garbage collection or at program exit. But as @delnan noted, it's better practice to explicitly close it for various reasons.
So, what you can do to keep ...