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Python: Is it bad form to raise exceptions within __init__?
Is it considered bad form to raise exceptions within __init__ ? If so, then what is the accepted method of throwing an error when certain class variables are initialized as None or of an incorrect type?
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Calling a class function inside of __init__
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Call the function in this way:
self.parse_file()
You also need to define your parse_file() function like this:
def parse_file(self):
The parse_file method has to be bound to an object upon calling it (because it's not a static method). This is done by calling t...
TypeError: got multiple values for argument
...ng of the box to another function, relaying all extra arguments.
def color_box(color, *args, **kwargs):
painter.select_color(color)
painter.draw_box(*args, **kwargs)
Then the call
color_box("blellow", color="green", height=20, width=30)
will fail because two values are assigned to colo...
partial string formatting
...he advanced string formatting methods, similar to the string template safe_substitute() function?
21 Answers
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Redirecting from HTTP to HTTPS with PHP
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Try something like this (should work for Apache and IIS):
if (empty($_SERVER['HTTPS']) || $_SERVER['HTTPS'] === "off") {
$location = 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
header('HTTP/1.1 301 Moved Permanently');
header('Location: ' . $location);
exit;
}...
How do I add a placeholder on a CharField in Django?
...t specify the field (e.g. for some dynamic method), you can use this:
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
self.fields['email'].widget.attrs['placeholder'] = self.fields['email'].label or 'email@address.nl'
It also allows the placeholder to de...
How to len(generator()) [duplicate]
...e advantages over functions that return lists. However, you could len(list_returning_function()) . Is there a way to len(generator_function()) ?
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error LNK2019: 无法解析的外部符号_socket，该符号在函数 中被引用 - C/C+...
error LNK2019: 无法解析的外部符号_socket，该符号在函数 中被引用1>NetClient.obj : error LNK2019: 无法解析的外部符号 _closesocket@4，该符号在函数 _main 中被引用1>NetClient.obj : error L...1>NetClient.obj : error LNK2019: 无法解析的外部符号 _closesocket@...
What is the most efficient way of finding all the factors of a number in Python?
...om functools import reduce
def factors(n):
return set(reduce(list.__add__,
([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0)))
This will return all of the factors, very quickly, of a number n.
Why square root as the upper limit?
sqrt(x) * sqrt(x) = x. So if t...
Convert nested Python dict to object?
...']
The alternative (original answer contents) is:
class Struct:
def __init__(self, **entries):
self.__dict__.update(entries)
Then, you can use:
>>> args = {'a': 1, 'b': 2}
>>> s = Struct(**args)
>>> s
<__main__.Struct instance at 0x01D6A738>
>>...