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Python's equivalent of && (logical-and) in an if-statement
...actually
evaluated because of the print statements:
>>> def print_and_return(value):
... print(value)
... return value
>>> res = print_and_return(False) and print_and_return(True)
False
As you can see only one print statement is executed, so Python really didn't even lo...
Does Python have an ordered set?
... the signature for .union doesn't match that of set, but since it includes __or__ something similar can easily be added:
@staticmethod
def union(*sets):
union = OrderedSet()
union.union(*sets)
return union
def union(self, *sets):
for set in sets:
self |= set
...
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 to get a complete list of object's methods and attributes?
...nts accepted by the getattr built-in function. As the user can reimplement __getattr__, suddenly allowing any kind of attribute, there is no possible generic way to generate that list. The dir function returns the keys in the __dict__ attribute, i.e. all the attributes accessible if the __getattr__ ...
C++及Windows异常处理(try，catch; __try,__finally, __except) - C/C++ - ...
C++及Windows异常处理(try，catch; __try,__finally, __except)C++及Windows异常处理(try，catch; __try,__finally; __try, __except)一道笔试题引起的探究题目：
int* p = 0x00000000; // pointer to NULL
puts( "hello ");
__try{
puts( "in try ...
Are static class variables possible in Python?
...es are one honking great idea -- let's do more of those!
>>> Test.__dict__
{'i': 6, ...}
>>> t.__dict__
{'i': 5}
>>> u.__dict__
{}
Notice how the instance variable t.i got out of sync with the "static" class variable when the attribute i was set directly on t. This is be...
Why does Python use 'magic methods'?
...s', e.g. to make its length available, an object implements a method, def __len__(self) , and then it is called when you write len(obj) .
...
Is there a TRY CATCH command in Bash
...ojects:
trycatch.sh
#!/bin/bash
function try()
{
[[ $- = *e* ]]; SAVED_OPT_E=$?
set +e
}
function throw()
{
exit $1
}
function catch()
{
export ex_code=$?
(( $SAVED_OPT_E )) && set +e
return $ex_code
}
function throwErrors()
{
set -e
}
function ignoreErrors()...
C++ mark as deprecated
...his all I got was a Microsoft specific solution; #pragma deprecated and __declspec(deprecated) .
7 Answers
...
what does the __file__ variable mean/do?
...
When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.
Taking your examples one at a time:
A = os.path.join(os.path.dirname(__file__), '..')
# A is the par...