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Python

Posted by Myles Brathwaite
Myles Brathwaite
1,971 Points

Difference between f'str' and format method?

I am confused between the use of f 'str' and the format method as they seem like they serve the same purpose. Is there a situation where the format method is the better option to use over the f 'str'? Example given below

groceries = ['roast beef', 'cucumbers', 'lettuce', 'peanut butter', 'bread', 'dog food']

index = 1
for item in groceries:
    print(f'{index}. {item}')
    index += 1

count = 1    
for item in groceries:
    print("{}. {}".format(index, item)) 
    count += 1

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,468 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,468 Points

The newer f-string format has faster execution and is more readable in many cases. The format() method is still useful when you want to unpack a container (list, str, etc.)

# using format
>>> s= 'abcde'
>>> s
‘abcde’
>>> print('{}-{}-{}'.format(*s[1:4]))
b-c-d

# using f-string It would more typing
>>> print(f'{s[1]}-{s[2}-{s[3]}')
b-c-d
# or using clearer when adding a step 
>>> x, y, z = s[1:4]
>>> x, y, z
(‘b’, ‘c’, ‘d’)
>>> print(f'{x}-{y}-{z}')
b-c-d

Post back if you need more help. Good luck!!!