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What is recursion and when should I use it?
...anguage implementations (i.e. every major implementation of C, C++, Basic, Python, Ruby,Java, and C#) iteration is vastly preferable to recursion.
To see why, walk through the steps that the above languages use to call a function:
space is carved out on the stack for the function's arguments and ...
An algorithm for inflating/deflating (offsetting, buffering) polygons
...at wants to do this, another alternative is to use GEOS, and if your using python, GEOS's wrapper, Shapely. A really pretty example: toblerity.github.com/shapely/manual.html#object.buffer
– pelson
Oct 3 '12 at 8:04
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Check if two unordered lists are equal [duplicate]
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Python has a built-in datatype for an unordered collection of (hashable) things, called a set. If you convert both lists to sets, the comparison will be unordered.
set(x) == set(y)
Documentation on set
EDIT: @mdwhatcott...
Read specific columns from a csv file with csv module?
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Context: For this type of work you should use the amazing python petl library. That will save you a lot of work and potential frustration from doing things 'manually' with the standard csv module. AFAIK, the only people who still use the csv module are those who have not yet discove...
How to take column-slices of dataframe in pandas
...at']
# foo bar quz ant cat sat
.loc accepts the same slice notation that Python lists do for both row and columns. Slice notation being start:stop:step
# slice from 'foo' to 'cat' by every 2nd column
df.loc[:, 'foo':'cat':2]
# foo quz cat
# slice from the beginning to 'bar'
df.loc[:, :'bar']
# f...
Django: Get list of model fields?
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@mpen Wont claim it the best way or the most pythonic but below will/should get the values u would want to display in a view, so the headers of an HTML table if u will. As get_fields() returns a tuple, u can iterate over it and get the values that look like appname.Mo...
Error handling in getJSON calls
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If possible, this seems like the easiest solution. Here's a sample of the Python code I used. (Using Flask, Flask's jsonify f and SQLAlchemy)
try:
snip = Snip.query.filter_by(user_id=current_user.get_id(), id=snip_id).first()
db.session.delete(snip)
db.session.commit()
return jsoni...
Is a statically-typed full Lisp variant possible?
...n't count as static typing. If it did, then Pypy would be statically typed Python since it also uses gradual typing.
– Björn Lindqvist
Apr 15 '19 at 15:02
2
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Recursion or Iteration?
...a stack frames; the penalty for this varies. Also, in some languages like Python (more correctly, in some implementations of some languages...), you can run into stack limits rather easily for tasks you might specify recursively, such as finding the maximum value in a tree data structure. In these...
Search and replace in bash using regular expressions
...l" or PCRE extensions \s\S\w\W\d\D etc don't work as supported in php ruby python etc. These extensions are from Perl-compatible regular expressions (PCRE) and may not be compatible with other forms of shell based regular expressions.
These don't work:
#!/bin/bash
hello=ho02123ware38384you443d34o...