fruit = 'apple'
print(fruit .upper())

prints,

APPLE

fruit = 'APPLE'
print(fruit .lower())

prints,

apple

fruit = 'apple'
find = fruit.find('le')
print(find)

a p p l e

1 2 3 4 5

it prints,

3

greet = "hello, Shafni"
replc = greet.replace('e','a')
print(replc)

prints,

hallo, Shafni

greet = "Yoo, Shafni"
replc = greet.replace('Yoo','hello').replace('Shafni', 'Bro')
print(replc)

prints,