Python3 list
Python sequence is the most basic data structure. Each element in the sequence is assigned a number - its position, or index, the first index is 0, the second index is 1, and so on.
Python has a built-in type 6 sequences, but the most common are lists and tuples.
The sequence of operations can be carried out, including indexing, slicing, add, multiply, check members.
Further, Python already built determined sequence length and determining the maximum and minimum element method.
Python is a list of the most common types of data, it can appear as a comma-separated values in square brackets.
Data items list need not have the same type
Create a list, as long as the comma-separated data items using different brackets can be. As follows:
list1 = ['Google', 'Runoob', 1997, 2000]; list2 = [1, 2, 3, 4, 5 ]; list3 = ["a", "b", "c", "d"];
The subscript index to access the values in the list, you can also use the same form of brackets taken character, as follows:
#!/usr/bin/python3
list1 = ['Google', 'Runoob', 1997, 2000];
list2 = [1, 2, 3, 4, 5, 6, 7 ];
print ("list1[0]: ", list1[0])
print ("list2[1:5]: ", list2[1:5])
You can modify or update data items in the list, you can also add a list item using append () method, as follows:
! # / usr / bin / python3 List = [ 'Google', 'Runoob', 1997, 2000] : Print (, List [2] "The third element is") List [2] = 2001 post-print ( "Update the third element is: ", list [2])
You can use the del statement to delete the list of elements, the following examples:
! # / usr / bin / python3 List = [ 'Google', 'Runoob', 1997, 2000] Print ( "the original list:", list) del List [2] Print ( "delete the third element:", list )
Similar lists of + and * operators string. + Number combination for the list, the list for repeatedly asterisk.
As follows:
len ([1, 2, 3]) # obtain a list of length [1, 2, 3] + [4, 5, 6] -> [1, 2, 3, 4, 5, 6] # list merge [ ' hi '] * 4 -> [ '!!!!! hi ',' hi ',' hi ',' hi '] # repeat string 3 in [1, 2, 3 ] -> True # whether the element present in the list for x in [1, 2, 3]: print (x, end = "") -> 1 2 3 # iterations
List interception
L [0: 2] # intercept the first character to a third character L [-1] # reads the first element of the inverse of L [1:] # after acquiring all the elements from the second element
Python list of functions & methods
Get a list of elements number len (list)
Returns the list of elements the maximum value max (list)
Returns a list of the minimum element min (list)
Converting the tuple list list (seq)
Add new object at the end of the list list.append (obj)
The number of times an element statistics appear in the list list.count (obj)
A plurality of values in another sequence added at the end of the list of one-time (original extended list with a new list) list.extend (SEQ) SEQ - element list may be a list of tuples, sets, dictionary, if a dictionary, only then will the key (key) as an element in turn added to the end of the original list. Examples #! / Usr / bin / python3 List1 = [ 'Google', 'Runoob', 'Taobao'] list2 = List (the Range (5)) # create a list of 0-4 list1.extend (list2) # expanded list print ( "the expanded list:", list1) a list of the extended: [ 'Google', 'Runoob ', 'Taobao', 0, 1, 2, 3, 4]
A value index to find the location of the first match from the list list.index (obj)
The object is inserted into the list, index inserted before which the subscript list.insert (index, obj)
Removing one element in the list (default to the last element), and returns the value of the element list.pop ([index = -1])
Reverse arrangement of elements in the list list.reverse ()
Clear List list.clear ()
Copy the list list.copy ()
Original list is sorted descending reverse = true indicates list.sort (key = None, reverse = False)
Remove the list a value of the first match list.remove (obj)