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Why can a function modify some arguments as perceived by the caller, but not others?
I'm trying to understand Python's approach to variable scope. In this example, why is f() able to alter the value of x , as perceived within main() , but not the value of n ?
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How to check if an object is a list or tuple (but not string)?
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In python 2 only (not python 3):
assert not isinstance(lst, basestring)
Is actually what you want, otherwise you'll miss out on a lot of things which act like lists, but aren't subclasses of list or tuple.
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Is it acceptable and safe to run pip install under sudo?
I've started to use my Mac to install Python packages in the same way I do with my Windows PC at work; however on my Mac I've come across frequent permission denied errors while writing to log files or site-packages.
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What is the use of “assert” in Python?
...condition, and immediately trigger an error if the condition is false.
In Python, it's roughly equivalent to this:
if not condition:
raise AssertionError()
Try it in the Python shell:
>>> assert True # nothing happens
>>> assert False
Traceback (most recent call last):
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How to comment out a block of code in Python [duplicate]
Is there a mechanism to comment out large blocks of Python code?
19 Answers
19
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Iterating through a JSON object
..., json_object[0][song].
None of this is specific to JSON. It's just basic Python types, with their basic operations as covered in any tutorial.
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Remove all the elements that occur in one list from another
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Python has a language feature called List Comprehensions that is perfectly suited to making this sort of thing extremely easy. The following statement does exactly what you want and stores the result in l3:
l3 = [x for x in ...
Inserting a Python datetime.datetime object into MySQL
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J McMahon: time is a Python module.
– dstromberg
Sep 1 '16 at 23:45
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Is it possible to have multiple statements in a python lambda expression?
I am a python newbie trying to achieve the following:
17 Answers
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What exactly are iterator, iterable, and iteration?
... is the most basic definition of "iterable", "iterator" and "iteration" in Python?
13 Answers
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