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ImportError: Cannot import name X
.... This is extremely important in C++, and even if it's not the #1 thing in Python, it's still a really good idea to follow this rule. Never have two classes which know each other, ever. If you need help with creating the structure for your classes, post rest of the code too. How exactly (in terms of...
Create numpy matrix filled with NaNs
...atives a[:] = numpy.nan here and a.fill(numpy.nan) as posted by Blaenk:
$ python -mtimeit "import numpy as np; a = np.empty((100,100));" "a.fill(np.nan)"
10000 loops, best of 3: 54.3 usec per loop
$ python -mtimeit "import numpy as np; a = np.empty((100,100));" "a[:] = np.nan"
10000 loops, best of...
File I/O in Every Programming Language [closed]
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Python 3
with open('fileio.txt', 'w') as f:
f.write('hello')
with open('fileio.txt', 'a') as f:
f.write('\nworld')
with open('fileio.txt') as f:
s = f.readlines()[1]
print(s)
Clarifications
readlines() returns a...
Python string.join(list) on object array rather than string array
In Python, I can do:
4 Answers
4
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How to make a variadic macro (variable number of arguments)
... C++ folks would like to encourage use of C++. Others do disagree, though; Linux Torvalds, for instance, has apparently rejected multiple proposed Linux-kernel patches that attempt to replace the identifier class with klass to permit compiling with a C++ compiler. Also note that there are some diffe...
Python - json without whitespaces
...hile indent=None (default) does not in 2.7. All is clearly stated at: docs.python.org/3/library/json.html#json.dump
– Ciro Santilli 郝海东冠状病六四事件法轮功
Jul 28 '16 at 14:01
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OSError: [Errno 2] No such file or directory while using python subprocess in Django
I am trying to run a program to make some system calls inside Python code using subprocess.call() which throws the following error:
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Windows equivalent to UNIX pwd
...te: While on Windows cd alone will print the current working directory, on Linux it will change to your user's home directory without printing anything. So beware if you're looking for something cross platform.
– Daniel Stevens
Aug 31 '18 at 9:29
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Python: split a list based on a condition?
...ramming (Haskell), or functional style (LINQ) is raised, we start to smell Python for its age - [x for x in blah if ...] - verbose, lambda is clumsy and limited... It feels like driving the coolest car from 1995 today. Not the same as back then.
– Tomasz Gandor
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How to check if a list is empty in Python? [duplicate]
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