Search & Reverse a List

Finding a Targetted Value

.index(target, start, end) method will find the first occurance of the target if it exists.

• If the target does not exist, it raises and error

• Both start and end arguments are optional

  • They act like slicing mechanism, we can look for the index of a value within such boundaries

# .index() example

a_list = ['apple', 'oranges', 'kiwi', 'honeydew', 'apple']

print("a_list.index('oranges'):", a_list.index('oranges'))
print("a_list.index('kiwi', 1, 5):", a_list.index('kiwi', 1, 5))

a_list.index('oranges'): 1
a_list.index('kiwi', 1, 5): 2

Counting the Number of Occurrence of a Target

.count(target) method counts the number of times target occurs.

• If target does not exist, returns 0

# .count() example

a_list = ['apple', 'oranges', 'kiwi', 'honeydew', 'apple']

print("a_list.index('oranges'):", a_list.count('oranges'))
print("a_list.index('apple'):", a_list.count('apple'))
print("a_list.index('strawberry'):", a_list.count('strawberry'))

a_list.index('oranges'): 1
a_list.index('apple'): 2
a_list.index('strawberry'): 0

Mutate and Reverse a list

.reverse() will reverse the order of the items in the list

# .reverse() example

a_list = ['apple', 'oranges', 'kiwi', 'honeydew', 'apple']
a_list.reverse()

print('a_list is now:', a_list)

a_list is now: ['apple', 'honeydew', 'kiwi', 'oranges', 'apple']