Python Lists :

Python Collections (Arrays) :

There are four collection data types in the Python programming language :

  1. List is a collection which is ordered and changeable. Allows duplicate members.
  2. Tuple is a collection which is ordered and changeable. Allows duplicate members.
  3. Set is a collection which is ordered and changeable. Allows duplicate members.
  4. Dictionary is a collection which is ordered and changeable. Allows duplicate members.

A list is a sequence :

Like a string, a list is a sequence of values. In a string, the values are characters; in a list, they can be any type. The values in a list are called elements or sometimes items. There are several ways to create a new list; the simplest is to enclose the elements in square brackets ( [ and ] ): 1. [10,20,30,40] 2. ["your name","your age","address"]
The first example is a list of four integers. The second is a list of three strings. The elements of a list don’t have to be the same type. python also have nested list feature (A list within another list is nested) : ["ayan",1,["age",24]]


Creating and Accessing Values in list :

Creating a list is as simple as putting different comma-separated values between square brackets. To access values in lists, use the square brackets for slicing along with the index or indices to obtain value available at that index.

Example :

  1. ourlist = ["ayan","rayan","apu","dev"]
  2. print(ourlist) #print full list
  3. print(ourlist[1]) #Print the second item of the list (start with 0)
  4. ourlist[1]="symul" #Change / Updating the second item
  5. print(ourlist) #print updated list items
  6. input()

Output :

python list examples

Loop Through a List :

You can loop through the list items by using a for loop:

Example :

  1. ourlist = ["ayan","rayan","apu","dev"]
  2. for x in ourlist : print(x) #Print all items in the list, one by one
  3. input()

Output :

python list with for loop

Check if Item Exists :

To determine if a specified item is present in a list use the in keyword:

Example :

  1. ourlist = ["ayan","rayan","apu","dev"]
  2. if "ayan" in ourlist : print("Yes, 'ayan' is in the list") #Check if "ayan" in the list
  3. input()

Output :

python list with if statement

List with methods :

python list have built-in methods, methods help us to manipulate list items.

Example :

  1. ourlist = ["ayan","rayan","apu","dev"]
  2. ourlist.append("rayan") #Using the append() method to append/adding an item
  3. print(ourlist)
  4. print(len(ourlist)) #Print the number of items in the list
  5. ourlist.insert(1,"alex") #Insert an item as the second position
  6. print(ourlist)
  7. ourlist.remove("rayan") #The remove() method removes the specified item
  8. print(ourlist)
  9. input()

Output :

python list with methods

List methods :

Python includes many built-in methods but here we just adding some of the following built-in methods to manipulate lists :

  • The len() method determine how many items a list has.
  • The append() method add an item to the end of the list.
  • The insert() method add an item at the specified index.
  • The remove() method are several methods to remove items from a list.
  • The pop() method removes the specified index, (or the last item if index is not specified).
  • The remove() method are several methods to remove items from a list.
  • The reverse() method are reverses the order of the list.
  • The sort() method are sorts the list.

Next Update

Loading...

Currently we improved our website User Interface and other contents. Our next update is adding video tutorials on this site so, We create a new YouTube channel, our YouTube channel name is CodeX.

We need some time for make video tutorials (CodeX) so, stay with us and keep supporting and you know already we make a Collaboration with HackIsOn YouTube channel long time ago So, please Subscribe Our Channels