Python str.format versus concatenation

Question

Hi there. So I always notice that Kenneth consistently uses str.format to show variables within strings. When I dink around with Python on my own, I usually use concatenation, because it puts the variable name where it should actually be inserted. </br>Kenneth's way:

new_item = "apples"
print("Your new item is {}. ".format(new_item))

How I would be more inclined to do it:

new_item = "apples"
print("Your new item is " + new_item + ". ")

Is either more professional/more common in the Python community or does it just come down to a personal style choice? Thanks!

Answer 1 · 2016-01-04T19:18:42Z

January 4, 2016 7:18pm

Hi Sam

I personally like the format method mostly because i can insert variables exactly where i want to in a string. It also come really handy if you want to unpack a dictionary. Consider this example below

#function thats takes a dictionary as a argument 

def my_details(dict):
    return("My name is {name} and i was born on {dob}!".format(**dict))


print(my_details({"name":"heman","dob":"who knows"}))

Output is :  My name is heman and i was born on who knows!  

# consider this case too
name = "heman"
dob = "who knows"

# i want to insert these variables in a string but i have to watch where the " end and start inorder to get the spacing correct

"My name is "+name+" and i was born on "+dob

# consider the format function its much easier, i dont need to worry about spacing as such

"I am {} and i was born on {}".format(name,dob)

so format is alot more handy a function to use not to meantion it makes inserting variables in a string so easy.

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Sam Dale

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Python str.format versus concatenation

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Andreas cormack

Andreas cormack

Sam Dale

Sam Dale