Difference between revisions of "Python"
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; else : print "Hash has some data" | ; else : print "Hash has some data" | ||
</pre> | </pre> | ||
+ | |||
+ | === Strings === | ||
+ | |||
+ | Use <code>"'{0}' is longer than '{1}'".format(name1, name2)</code> | ||
+ | |||
+ | The old-style % formatting uses % codes for formatting: | ||
+ | |||
+ | <code>'It will cost $%d dollars.' % 95</code> | ||
+ | The new-style {} formatting uses {} codes and the .format method | ||
+ | |||
+ | <code>'It will cost ${0} dollars.'.format(95)</code> | ||
+ | Note that with old-style formatting, you have to specify multiple arguments using a tuple: | ||
+ | |||
+ | <code>'%d days and %d nights' % (40, 40)</code> |
Revision as of 02:16, 11 February 2020
Data Types
int 1234 >>> type(1234) <class 'int'> float 55.50 >>> type(55.50) <class 'float'> complex >>> type(6+4j) <class 'complex'> string hellow >>> type("hello") <class 'str'> Square list [1,2,3,4] >>> type([1,2,3,4]) <class 'list'> Round tuple (1,2,3,4) >>> type((1,2,3,4)) <class 'tuple'> Curly dict {1:"one", 2:"two", 3:"three"} >>> type({1:"one", 2:"two", 3:"three"}) <class 'dict'>
Python version of a perl hash
import collections ; def tree() : return collections.defaultdict(tree) hash = tree() hash[['outer_key']][['inner key']] = "value" ; if not bool(hash) : print "Hash is empty" ; else : print "Hash has some data"
Strings
Use "'{0}' is longer than '{1}'".format(name1, name2)
The old-style % formatting uses % codes for formatting:
'It will cost $%d dollars.' % 95
The new-style {} formatting uses {} codes and the .format method
'It will cost ${0} dollars.'.format(95)
Note that with old-style formatting, you have to specify multiple arguments using a tuple:
'%d days and %d nights' % (40, 40)