What is the meaning of invalid literal for int() with base = ' '?

ValueError is encountered when we pass an inappropriate argument type. Here, we are talking about the ValueError caused by passing an incorrect argument to the int() function. When we pass a string representation of a float or any string representation other than that of int, it gives a ValueError. Example 1 : ValueError with base 10. Python3

# ValueError caused by conversion of 
# String representation of float to int
int('23.5')

Output :

ValueError: invalid literal for int() with base 10: '23.5'

One can think that while executing the above code, the decimal part ‘.5’ should be truncated and the code should give output as 23 only. But the point to be noted is that the int( ) function uses the decimal number system as its base for conversion ie. base = 10 is the default value for conversion. And in the decimal number system, we have numbers from 0 to 9 excluding the decimal (.) and other characters(alphabets and special chars). Therefore, int() with base = 10 can only convert a string representation of int and not floats or chars. We can first convert the string representation of float into float using float() function and then convert it into an integer using int(). Python3

print(int(float('23.5')))

Output :

23

Example 2 : Passing alphabets in int(). Python3

int('abc')

Output :

invalid literal for int() with base 10: 'abc'

The chars a, b, c, d, e, and f are present in the base =16 system and therefore only these chars along with digits 0 to 9 can be converted from their string representation to integer in hexadecimal form. We have to pass an parameter base with value 16. Python3

print(int('abc', base = 16))

Output :

2748