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Why is Python 3.x's super() magic?
In Python 3.x, super() can be called without arguments:
1 Answer
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Referring to the null object in Python
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SyntaxError: cannot assign to keyword
It's therefore safe to assume that all None references are the same. There isn't any "custom" None.
To test for None use the is operator
When writing code you might be tempted to test for Noneness like this:
if value==None:
pass
Or to test for falsehood l...
How to “perfectly” override a dict?
...or other builtins) directly. It often makes no sense, because what you actually want to do is implement the interface of a dict. And that is exactly what ABCs are for.
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In the shell, what does “ 2>&1 ” mean?
...ay look like a good way to redirect stderr to stdout. However, it will actually be interpreted as "redirect stderr to a file named 1". & indicates that what follows is a file descriptor and not a filename. So the construct becomes: 2>&1.
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How can I join elements of an array in Bash?
... +1. What about printf -v bar ",%s" "${foo[@]}". It is one fork less (actually clone). It is even forking reading a file: printf -v bar ",%s" $(<infile).
– TrueY
Jun 8 '13 at 22:55
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Calling a function of a module by using its name (a string)
What is the best way to go about calling a function given a string with the function's name in a Python program. For example, let's say that I have a module foo , and I have a string whose content is "bar" . What is the best way to call foo.bar() ?
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partial string formatting
...ct):
def __missing__(self, key):
return "{" + key + "}"
s = '{foo} {bar}'
formatter = string.Formatter()
mapping = FormatDict(foo='FOO')
print(formatter.vformat(s, (), mapping))
printing
FOO {bar}
Of course this basic implementation only works correctly for basic cases.
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private[this] vs private
...rotected over public doesn't apply.
Use private[this] where performance really matters (since you'll get direct field access instead of methods this way). Otherwise, just settle on one style so people don't need to figure out why this property is private and that one is private[this].
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Why aren't python nested functions called closures?
...s in Python, and they match the definition of a closure. So why are they called nested functions instead of closures ?
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What is a “callable”?
...t's clear what a metaclass is , there is an associated concept that I use all the time without knowing what it really means.
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