Tuple format
(Element 1, element 2, element 3, ...)
Elements can be accessed, but can not be modified
Nested list
List name [] []
print (id (variable name)) to obtain the address of the variable value
List, an ordered set of tuples, dictionaries unordered collections
dictionary
The only type of mapping python
format
Dictionary name = { 'key', 'value', ...} or dictionary name = dict ( 'key,' value ')
Immutable type: integer, string, a tuple
Variable types: lists, dictionaries
use
By looking for the value of the key, the key can only be immutable
print (name dictionary [ 'key'])
increase
Name dictionary [ 'key'] = 'value' if the key is present, then the new value overwrites the old value does not exist, add to the dictionary
Dictionary name .setdefault ( 'key', 'value') if the key is present, no effect, does not exist, add to the dictionary and return values
check
print (name dictionary [ 'key'])
Dictionary name .keys () to find all the keys
Dictionary name .values () Find all values
Dictionary name .items () to find all keys
change
Name dictionary [ 'key'] = 'new value'
Dictionary a.update (dictionary b) adding to the dictionary b keys in a dictionary, if the same key, the original value of the coverage
delete
Dictionary name .clear () clears dictionary
del dictionary name [ 'key'] Delete the specified key
Dictionary name .pop ( 'key') to delete the specified key, and returns a value dictionary name .pop () to delete a random key
Dictionary name .popitem () delete a random set of keys, and returns a tuple method
Other operations
dict.fromkeys ([ 'key 1', 'key 2', ..], 'value') of the specified value is assigned to the specified key
Nested dictionary
Dictionary name = { 'key': {}, ..}
Sequence
sorted (dictionary name) button from small to large
sorted (dictionary name .values ()) by value from small to large
Dictionary traversal
for i in dictionary name:
print (i, Dictionary names [i])
for i in the dictionary name .items () returns a value tuple type
Character Transfer
\' apostrophe
\'' Double quotes
\ T Tab
\ N newline
\\ slash down
String sections
'String' [;]
in judgment
'Partial string' in 'string'
The method of connection string
· ''. Join () connected to one string for
String built-in method
count () calculates the number of occurrences string
capitalize () first letter capitalized
center () center
endwith () to determine whether an end with the specified content, in line with True, and vice versa Flase
startwith () to determine whether to start with a specified content, in line with True, and vice versa Flase
How many spaces expandtabs (tabsize =) Set the escape character tabs
find () search string from left to right, which returns the index to find the value, a value of -1 is not found
format () formatted output
name = ’I am {name}'
name.format(name=' ')
format_map () parameter as a dictionary
index () to find the string index value is returned, not found error
.isalnum () determines whether the numbers and letters, and non-empty, is True
.isdecimal () determines whether or contain only numbers, and non-empty, is True
.isalpha () determines whether or contain only letters, and non-empty, is True
.isdigit () determines whether an integer
.isspace () determines whether only contains space, tab, newline
.istitle () to determine whether the first letter capitalized, and followed by lowercase letters of the word
.isidentifier () determines illegal identifier
Whether .islower () are judged to lowercase
Whether .isupper () to determine both uppercase
.lower () uppercase to lowercase
.upper () becomes uppercase lowercase
.swapcase () uppercase to lowercase, uppercase lowercase change
.ljust () Left
.rjust () right justified
.strip () to delete the character left and right blank
.lstrip () to delete the character left blank
.rstrip () Delete character right margin
.replace ( 'old', 'new') replacement string
.rfind () to find the string from right to left and returns the index value
.split () divided by parameter a delimiter string, it returns a list of
.rsplit () right to left, divided by a parameter string delimiter, returns a list of
.title () first letter capitalized, followed by lower case letters of the word