Appendix F. Cheat Sheets
I find myself looking up certain things a little too often. Here are some tables that I hope you’ll find useful.
Operator Precedence
This table is a remix of the official documentation on precedence in Python 3, with the highest precedence operators at the top.
| Operator | Description and examples |
|---|---|
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List/set/dict/generator creation or comprehension, parenthesized expression |
seq |
Index, slice, function call, attribute reference |
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Exponentiation |
`+`x, `-`x, `~`x |
Positive, negative, bitwise |
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Multiplication, float division, int division, remainder |
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Addition, subtraction |
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Bitwise left, right shifts |
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Bitwise |
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Bitwise |
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Membership and equality tests |
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Boolean (logical) |
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Boolean |
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Boolean |
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Conditional expression |
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String Methods
Python offers both string methods (can be used with any str object) and a string
module with some useful definitions. Let’s use these test variables:
>>>s="OH, my paws and whiskers!">>>t="I'm late!"
Change Case
>>>s.capitalize()'Oh, my paws and whiskers!'>>>s.lower()'oh, my paws and whiskers!'>>>s.swapcase()'oh, MY PAWS AND WHISKERS!'>>>s.title()'Oh, My Paws And Whiskers!'>>>s.upper()'OH, MY PAWS AND WHISKERS!'
Search
>>>s.count('w')2>>>s.find('w')9>>>s.index('w')9>>>s.rfind('w')16>>>s.rindex('w')16>>>s.startswith('OH')True
Modify
>>>''.join(s)'OH, my paws and whiskers!'>>>' '.join(s)'O H , m y p a w s a n d w h i s k e r s !'>>>' '.join((s,t))"OH, my paws and whiskers! I'm late!">>>s.lstrip('HO')', my paws and whiskers!'>>>s.replace('H','MG')'OMG, my paws and whiskers!'>>>s.rsplit()['OH,', 'my', 'paws', 'and', 'whiskers!']>>>s.rsplit(' ',1)['OH, my paws and', 'whiskers!']>>>s.split()['OH,', 'my', 'paws', 'and', 'whiskers!']>>>s.split(' ')['OH,', 'my', 'paws', 'and', 'whiskers!']>>>s.splitlines()['OH, my paws and whiskers!']>>>s.strip()'OH, my paws and whiskers!'>>>s.strip('s!')'OH, my paws and whisker'
Format
>>>s.center(30)' OH, my paws and whiskers! '>>>s.expandtabs()'OH, my paws and whiskers!'>>>s.ljust(30)'OH, my paws and whiskers! '>>>s.rjust(30)' OH, my paws and whiskers!'
String Type
>>>s.isalnum()False>>>s.isalpha()False>>>s.isprintable()True>>>s.istitle()False>>>s.isupper()False>>>s.isdecimal()False>>>s.isnumeric()False
String Module Attributes
These are class attributes that are used as constant definitions.
| Attribute | Example |
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Fin
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No, wait…it isn’t.