Python List

Lists are used to store multiple items in a single variable

thislist= ['apple','banana','mango']
print(thislist)

List items are ordered, changeable, and allow duplicate values.

Length of lists

thislist = ["apple", "banana", "cherry"]  
print(len(thislist))
# 3

list1 = ["abc", 34, True, 40, "male"]
print(list1)
# ['abc', 34, True, 40, 'male']

Change value item in lists

thislist = ['yash','mahesh','bhangale']
thislist [1] = " "
print(thislist)

Insert item in lists

thislist = ['apple','mango','banana']
thislist.insert(2, "watermelon")
print(thislist)

Append items

To add an item to the end of the list, use the append() method:

thislist = ["apple", "banana", "cherry"]  
thislist.append("orange")  
print(thislist)
# ['apple', 'banana', 'cherry', 'orange']

Extend List

To append elements from another list to the current list, use the extend() method.

thislist = ["apple", "banana", "cherry"]  
tropical = ["mango", "pineapple", "papaya"]  
thislist.extend(tropical)  
print(thislist)
 
# ['apple', 'banana', 'cherry', 'mango', 'pineapple', 'papaya']

Remove specific item

The remove() method removes the specified item.

thislist = ["apple", "banana", "cherry"]  
thislist.remove("banana")  
print(thislist)
 
# ['apple', 'cherry']

Loop Lists

thislist = ["apple", "banana", "cherry"]  
for x in thislist:  
  print(x)

While loop

thislist = ["apple", "banana", "cherry"]  
i = 0  
while i < len(thislist):  
  print(thislist[i])  
  i = i + 1

Sort List Alphanumerically

List objects have a sort() method that will sort the list alphanumerically, ascending, by default:

thislist = ["orange", "mango", "kiwi", "pineapple", "banana"]  
thislist.sort()  
print(thislist)
 
# ------------------------------------------------------------- #
 
thislist = [100, 50, 65, 82, 23]  
thislist.sort()  
print(thislist)

Sort Desceding

To sort descending, use the keyword argument reverse = True:

thislist = ["orange", "mango", "kiwi", "pineapple", "banana"]  
thislist.sort(reverse = True)  
print(thislist)
 
#----------------------------------------------------------#
 
thislist = [100, 50, 65, 82, 23]  
thislist.sort(reverse = True)  
print(thislist)

Copy a List

You cannot copy a list simply by typing list2 = list1, because: list2 will only be a reference to list1, and changes made in list1 will automatically also be made in list2.

thislist = ["apple", "banana", "cherry"]  
mylist = thislist.copy()  
print(mylist)

Join Two Lists

There are several ways to join, or concatenate, two or more lists in Python. One of the easiest ways are by using the + operator.

list1 = ["a", "b", "c"]  
list2 = [1, 2, 3]  
  
list3 = list1 + list2  
print(list3)

list1 = ["a", "b" , "c"]  
list2 = [1, 2, 3]  
  
for x in list2:  
  list1.append(x)  
  
print(list1)

Notes

Explorer