Python type error | operator behaviour with str and int-CodePudding

print("*" * 10) this line in python print * 10 times.

However the when trying to print("*" 10) there is a type error.

Why is there a difference in operator behaviour with str and int

CodePudding user response：

That's because is a concatenator in Python, and you can concatenate two strings but not a string and an int. You can, of course, cast the int into a string and concatenate that with another string if that's what you want to do: print("*" (str(10)))

The thing works with * because that operator will simply concatenate the string with itself as many times as indicated by the integer number, as you've observed.

CodePudding user response：

Well, there is a difference because it is a different operator, and operations of addition between str and int have not been implemented in Python.

Mostly because it is ambiguous. What would print("*" 10) mean? Would it mean to concatenate the int as if it were a string as "*10", or to add 10 to each character's ASCII value, or to evaluate the string as an int and then apply normal addition? Because of this ambiguity, it has been left unimplemented.

CodePudding user response：

I hope you are well,

The asterisk (star)(*) operator is used in Python with more than one meaning attached to it.

a=10
b=20
a*b

returns 200, but For sequences such as string, list and tuple, * is a repetition operator

m="Hello World."
m*3

it returns , 'Hello World.Hello World.Hello World'

Single asterisk as used in function declaration allows variable number of arguments passed from calling environment. Inside the function it behaves as a tuple.

def function(*arg):
    for i in arg:
        print (i)

It returns all the items in the args.

You can import all the functions of a library or python script with using single star(*)

from math import *

but for the " " if you want to use between 2 variables with (int) and (str), it will give and error, because " " can sum same types together.

I hope it answers your doubt.