Ways to List Python

# last new element in list
Li = [11, 22, 33]
Print (LI)
Li.append  # Add an element to the original list last
Print (LI)
EXECUTE as follows:

[11, 22, 33]
[11, 22, 33, 44]

# empty List
Li = [11, 22, 33, 44, 55]
Li.clear ()   # empty list
Print (LI)

EXECUTE as follows: []

# Copy of List
Li = [22, 21, 32, 53]
bi = li.copy ()  # Copy a new list
Print (LI)
Print (BI)

EXECUTE as follows:

[22, 21, 32, 53]
[22, 21, 32, 53]

# Extend the existing list
Li = [23, 34, 25, 26]
Li.extend ("11") # expands two strings to the list
Print (LI)

[23, 34, 25, 26, ' 1 ', ' 1 ']

Li.extend ([93]) # Extend a list
Print (LI)

[23, 34, 25, 26, ' 1 ', ' 1 ', 93]

BI = [12, 423, 231]
Li.extend (BI) # expands another list to be added from behind the original list
Print (LI)

[23, 34, 25, 26, ' 1 ', ' 1 ', 93, 12, 423, 231]

Li = List ([1, 2, 3])
Print (LI)
Li.extend ([11, 22]) # Extend a list
Print (LI)
Li.extend ((911, 22)) # can also be a tuple
Print (LI)
EXECUTE as follows:

[1, 2, 3]
[1, 2, 3, 11, 22]
[1, 2, 3, 11, 22, 911, 22]

#  List Index
Li = [1, 2, 3, 4, 5]
Print (Li.index (5))  # Gets the lower label of the list element

EXECUTE as follows:
4

# list Insert

Li = [2, 2334, 11, 33]
Li.insert (2, ("A", "B", "C")  # Inserting a tuple at index 2
Print (LI)

[2, 2334, (' A ', ' B ', ' C '), 11, 33]

Li.insert (4, [[+])  # Insert a new list at index 4
Print (LI)

[2, 2334, (' A ', ' B ', ' C '), 11, [66, 33], 33]

Li.insert (1, "CC")  # Inserts an element at index 1
Print (LI)

[2, ' cc ', 2334, (' A ', ' B ', ' C '), 11, [66, 33], 33]

# When you remove a list element, it is used in the message queue
Li = [2, 2334, 11, 33]
ret = Li.pop ()  # Gets the value rejected, the last value is deleted by default
Print (LI)

[2, 2334, 11]

Print (ret)

33

Ret1 = Li.pop (0)   # Delete the element at the index and get the deleted value
Print (LI)

[2334, 11]

Print (RET1)

2

# Delete the value specified by the list
Li = [11, 22, 11, 22, 11]
Print (LI)
Li.remove (11) # Delete the list of an element, where it is non-indexed, and if there are duplicates delete only the first
Print (LI)

[11, 22, 11, 22, 11]
[22, 11, 22, 11]

# list Element inversion
Li = [11, 22, 33, 44, 55]
Print (LI)
Li.reverse () # Invert list elements
Print (LI)

[11, 22, 33, 44, 55]
[55, 44, 33, 22, 11]

# count the number of elements in a list
Li = [23, 342, 22, 42, 22]
CU = Li.count ($)  # counts the number of elements in a list
Print (CU)

2

#列表数组排序
Li = [22, 12, 212, 13, 423]
Li.sort ()
Print (LI)
[12, 13, 22, 212, 423]

 #如果需要一个排序好的副本，同时保持原有列表不变 a = [ 4 , 6 , 2 , 1 , 7 , 9 ] b = a[ : ] b.sort() print b #[1, 2, 4, 6, 7, 9] print a #[4, 6, 2, 1, 7, 9] #注意: b = a[:] Copy all the elements of List A to B through a shard operation, and if you simply assign a value to B:b = A, a or a to the same list, and do not produce a new copy

Ways to List Python