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Using a dictionary to count the items in a list [duplicate]
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in 2.7 and 3.1 there is special Counter dict for this purpose.
>>> from collections import Counter
>>> Counter(['apple','red','apple','red','red','pear'])
Counter({'red': 3, 'apple': 2, 'pear': 1})
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Format date and time in a Windows batch script
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33 Answers
33
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What's the difference between a proc and a lambda in Ruby?
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An example:
p = Proc.new {|a, b| puts a**2+b**2 } # => #<Proc:0x3c7d28@(irb):1>
p.call 1, 2 # => 5
p.call 1 # => NoMethodError: undefined method `**' for nil:NilClass
p.call 1, 2, 3 # => 5
l = lambda {|a, b| puts a**2+b**2 } # => #<Proc:0x15016c@(irb):5 (lambda)>
l.ca...
Find MongoDB records where array field is not empty
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873
If you also have documents that don't have the key, you can use:
ME.find({ pictures: { $exists:...
Regex to match a digit two or four times
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ruakhruakh
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Problems with lib-icu dependency when installing Symfony 2.3.x via Composer
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Intl::getIcuDataVersion();
attention: not needed anymore ( symfony 2.3 has meanwhile been released )
add the minimum stability flag @dev or @rc to your dependency like this please:
composer create-project symfony/framework-standard-edition mynewerproject/ 2.3.*@dev
The default stability i...
Python class inherits object
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831
Is there any reason for a class declaration to inherit from object?
In Python 3, apart fro...
Rename Pandas DataFrame Index
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243
The rename method takes a dictionary for the index which applies to index values.
You want to re...
Update multiple rows in same query using PostgreSQL
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453
+50
You can a...