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How can I find the number of arguments of a Python function?
...ms = sig.parameters
print(params['kwarg1']) # prints: kwarg1=20
Additionally, you can call len on sig.parameters to also see the number of arguments this function requires:
print(len(params)) # 3
Each entry in the params mapping is actually a Parameter object that has further attributes makin...
Standardize data columns in R
I have a dataset called spam which contains 58 columns and approximately 3500 rows of data related to spam messages.
15 ...
How can I distribute python programs?
...ugh I don't know how it works on Windows. You would on Windows have to install Python separately if you use distutils, in any case.
I'd probably recommend that you distribute it with disutils for Linux, and Py2exe or something similar for Windows. For OS X I don't know. If it's an end user applicat...
Curly braces in string in PHP
...nterpolation. From the manual:
Complex (curly) syntax
This isn't called complex because the syntax is complex, but because
it allows for the use of complex expressions.
Any scalar variable, array element or object property with a string
representation can be included via this synta...
Selecting multiple columns in a pandas dataframe
...).
df1 = df[['a', 'b']]
Alternatively, if it matters to index them numerically and not by their name (say your code should automatically do this without knowing the names of the first two columns) then you can do this instead:
df1 = df.iloc[:, 0:2] # Remember that Python does not slice inclusive of...
Renaming a virtualenv folder without breaking it
...
You need to adjust your install to use relative paths. virtualenv provides for this with the --relocatable option. From the docs:
Normally environments are tied to a
specific path. That means that you
cannot move an environment around or
copy ...
How do I override __getattr__ in Python without breaking the default behavior?
I want to override the __getattr__ method on a class to do something fancy but I don't want to break the default behavior.
...
How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?
Is there a way to call a block with a primitive parameter after a delay, like using performSelector:withObject:afterDelay: but with an argument like int / double / float ?
...
关于 __VA_ARGS__ 宽字符版本的问题 - C/C++ - 清泛网 - 专注C/C++及内核技术
关于 __VA_ARGS__ 宽字符版本的问题在写一个可变参数的记录日志函数，考虑到宽字符（Unicode版本）时：#define WIDEN2(x) L ## x#define WIDEN(x) WIDEN2(x)#define __...在写一个可变参数的记录日志函数，考虑到宽字符（Unicode版本）时：
#defin...
Compile time string hashing
... string length, and the compiler is not clever enough to elide the second call. Check other answers for possible fix for this problem.
– CygnusX1
Feb 27 '16 at 16:34
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