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Nested defaultdict of defaultdict
...
For an arbitrary number of levels:
def rec_dd():
return defaultdict(rec_dd)
>>> x = rec_dd()
>>> x['a']['b']['c']['d']
defaultdict(<function rec_dd at 0x7f0dcef81500>, {})
>>> print json.dumps(x)
{"a": {"b": {"c": {"d": {}}}}}
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How to read keyboard-input?
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try
raw_input('Enter your input:') # If you use Python 2
input('Enter your input:') # If you use Python 3
and if you want to have a numeric value
just convert it:
try:
mode=int(raw_input('Input:'))
except ValueError:
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What exactly does Perl's “bless” do?
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package Person;
sub new
{
my $class = shift;
my $self = {
_firstName => shift,
_lastName => shift,
_ssn => shift,
};
# Print all the values just for clarification.
print "First Name is $self->{_firstName}\n";
print "Last Name is $se...
How to read if a checkbox is checked in PHP?
...="value1">
After submitting the form you can check it with:
isset($_POST['test'])
or
if ($_POST['test'] == 'value1') ...
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Linux command or script counting duplicated lines in a text file?
...3
}
or you can use a simple one-liner:
$ cat filename | python3 -c 'print(__import__("json").dumps(__import__("collections").Counter(map(str.strip, __import__("fileinput").input())), indent=2))'
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Determine if variable is defined in Python [duplicate]
...()
if you want to be pedantic, you can check the builtins too
'a' in vars(__builtins__)
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Iterate an iterator by chunks (of n) in Python? [duplicate]
...', 'x') --> ABC DEF Gxx"
args = [iter(iterable)] * n
return izip_longest(fillvalue=fillvalue, *args)
It will fill up the last chunk with a fill value, though.
A less general solution that only works on sequences but does handle the last chunk as desired is
[my_list[i:i + chunk_size] f...
PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?
I did a lot of searching and also read the PHP $_SERVER docs . Do I have this right regarding which to use for my PHP scripts for simple link definitions used throughout my site?
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What is the difference between shallow copy, deepcopy and normal assignment operation?
... @grc But I have tried an example(I remove the new line here.) list_=[[1,2],[3,4]] newlist = list_.copy() list_[0]=[7,8] print(list_) print(newlist) The newlist still display [[1, 2], [3, 4]]. But list_[0] is a list which is mutable.
– Alston
Nov 12 '16...
AttributeError: 'module' object has no attribute 'tests'
... Instead of fearing use of the "death star" can't you juse use the __all__ variable in each file? And specify a list of class names, functions, and variables to export when using from package_name.module import *? I've had good luck with this pattern. I understand it takes a bit more time...