get the index of an element in a list python code example

Example 1: get index of list python

list.index(element)

Example 2: python find index by value

>>> ["foo", "bar", "baz"].index("bar")
1

Example 3: python find index of first matching element in a list

# Basic syntax:
list.index(element, start, end) 
# Where:
#	- Element is the item you're looking for in the list
# 	- Start is optional, and is the list index you want to start at
#	- End is option, and is the list index you want to stop searching at

# Note, Python is 0-indexed

# Example usage:
my_list = [1, 2, 3, 4, 5, 6, 7, 8, 42, 9, 10]
my_list.index(42)
--> 8

Example 4: python index of element in list

# alphabets list
alphabets = ['a', 'e', 'i', 'o', 'g', 'l', 'i', 'u']

# index of 'i' in alphabets
index = alphabets.index('i')   # 2
print('The index of i:', index)

# 'i' after the 4th index is searched
index = alphabets.index('i', 4)   # 6
print('The index of i:', index)

# 'i' between 3rd and 5th index is searched
index = alphabets.index('i', 3, 5)   # Error!
print('The index of i:', index)

Example 5: find index of sublist in list python

greeting = ['hello','my','name','is','bob','how','are','you','my','name','is']

def find_sub_list(sl,l):
    results=[]
    sll=len(sl)
    for ind in (i for i,e in enumerate(l) if e==sl[0]):
        if l[ind:ind+sll]==sl:
            results.append((ind,ind+sll-1))

    return results

print find_sub_list(['my','name','is'], greeting) 
# [(1, 3), (8, 10)]

Example 6: python list get index from value

["foo", "bar", "baz"].index("bar")

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Cpp Example