Examples of how to select nth element in a list with python:
Create a list
Let's first create a list with python:
mylist = ['A', 'B', 'C', 'D', 'E', 'F']
Note that a list is 0 based indexing.
| index | element |
|---|---|
| 0 | A |
| 1 | B |
| 2 | C |
| 3 | D |
| 4 | E |
| 5 | F |
Check the following link to learn more about different data structures in python.
Select the first element of a list
To select the first element of a list
mylist[0]
returns here
'A'
Select the last element of a list
To select the last element of a list
mylist[-1]
returns here
'F'
Select nth element of a list
To select nth element of a list
mylist[4]
returns here
'E'
However
mylist[6]
will returns the following error message
IndexError: list index out of range
since the list contains only 6 element.
To avoid that
index = 6if index < len(mylist):print(mylist[index])else:print('Warning: list index out of range')
or
try:mylist[index]except:pass
Find index of a given element
Note to find the index of a given element
mylist.index('D')
returns
3
Note: To check if an element is in a list:
'D' in mylist
returns
True
while
'G' in mylist
returns
False
Loop through a list and print element with associated index
To loop through a list and print element with associated index, a solution is to use enumerate()
for i,e in enumerate(mylist):print(i,e)
returns here
0 A1 B2 C3 D4 E5 F
