a=["sri",10,3.5,print]
a[0] //output: sri
a[3] //output: print
a[3]("HelloWorld") //output: HelloWorld
Some important properties of lists are
They are mutable
Ordered
Heterogenous
accessed using index
List are iterable
for index in a:
print(a[index])
output:
10
20
30
40
50
a[-1] will give the last element // 50
a[-2] will give the second last element //40
a[-3] will give the third last element and so on //30
Some of the basic list operations
- finding length
- concatinate
- repetition
- membership
- insert
- append
- pop
- remove
- del
- copy
- count
a=[10,20,30,40,50]
1)Find Length: len(a) output - 5
2)Concatinate (join two lists): a+a output - [10,20,30,40,50,10,20,30,40,50]
3)Repetition (repeat the same list number of times): a*2 output - [10,20,30,40,50,10,20,30,40,50]
4)Membership (check whether element is present in the list): 10 in a output - True
Updating list elements
Inserting element into list:
insert
append
5)Insert operation:
insert operation inserts an element to list at a fixed index.
my_list=["helloworld"]
my_list.insert(1,"happyDay")
print(my_list)
["helloworld","happyDay"]
6)Append operation:
append operation inserts the element at the end of the list.
my_list.append("happyCoding")
print(my_list)
["helloworld","happyDay","happyCoding"]
Deleting list elements
pop
delete
remove
my_list=["helloworld","happyDay","happyCoding"]
7)Pop opertion:
my_list.pop()
output: happyCoding (removes last element)
my_list.pop(0)
output: helloworld (when mentioned an index, removes element in that particular index)
Now,my_list has only one element in it.
my_list=["happyDay"]
8)Remove:
my_list.remove("happyDay") //removes 1st occurance of that string
My my_list is empty.
print(my_list)
[] output - an empty list.
9)Delete operation:
del(my_list) output - deletes the memory address of the list.
10)Copy:
my_new_list=my_list.copy() output - copies elements in my_list to my_new_list
11)Count:
my_list.count("element") output -returns count of specified element in my_list.
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