List
list.append ( 'XXX') - is added to the list of elements
list.extend ([ 'xx', 'yy']) - appended to the list of the plurality of elements
list .insert (1, 'xxx') - the element is inserted into the specified position
- The x, y, z values of the three variables swap
x , y , z = z ,y ,x
- Membership operator
in - for checking whether a value in the sequence
type () / isinstance () - Analyzing variable type
Example:
member =['a' , 'b' , 'c ']
- del member [1] - delete the second element
member.remove('a')
member.pop (1) - (the second member is removed from the element, the element is taken out is no longer in the list)
# Name = member.pop (1) is a
- member [0: 3] - the first three elements of the list to obtain
- member2 = member [:] - fragmentation Copy - copy and member2 = distinguished member - which member2 member will vary with changes
- List comprehensions - create a list dynamically
例： list 1 =[ i*i for i in range (10) ] —— list 1 = [ 0,1,4,9,16,25,36,49,64,81]
Is equivalent to: list 1 = []
for i in range (10):
list 1. append(i*i)
- list.sort () - ascending order --list.sort (reverse = True) - in descending order
- list.reverse () - list in reverse order
- list2 = list1.copy () - Copy list1
- list.clear () - clear the list of elements, list2 becomes empty list
- list.count ( 'xxx') - an element number appears in the list
- list.index ( 'xxx', 2, 7) - position of the search elements in the list; 2,7 starting and ending positions, i.e., range
Tuple
the tuple "," is the key
- temp1 = (1,) # only one tuple element, without parentheses
- temp2 = 2,3,4 # tuple with three elements
- 8*（8）——>64
- * 8 (8) -> (8,8,8,8,8,8,8,8) # "*" to repeat the operator
- All objects, comma separated, with no clear definition of the default set of symbols is a tuple type
x , y , z =1 , 2 , 3
type (x) =<class 'int'>
h= x , y , z
type (h)=<class 'tuple'>
Tuples and strings of changes, update
例：tuple1 [:6]+("xxx" , ) + tuple2 [6:]
str1 [:6] + 'xxx' + str1 [6:]
String
String methods and notes
Symbol Meaning format string and escape character meaning
s is a string
s.isalnum () All characters are numbers or letters, is true returns Ture, otherwise False.
s.isalpha () All characters are letters, is true returns Ture, otherwise False.
s.isdigit () All characters are numeric, true return Ture, otherwise False.
s.islower () are all lowercase characters, true return Ture, otherwise False.
s.isupper () All characters are uppercase, true return Ture, otherwise False.
s.istitle () all words are capitalized, is true returns Ture, otherwise False.
s.isspace () all characters are blank characters, true return Ture, otherwise False.
- Sequence - a listing of some BIF, tuples, strings
max()
(I)
sum () - sum (list1, 8) - the number of elements in list1 added together before adding 8
sorted () - in ascending order
list(reversed(numbers))
list (enumerate (numbers)) - generation of the index value of each element and the value of the item consisting tuple
list (zip (a, b)) - Returns a, b where the parameters a tuple