How does the following python code work?

Question

print(eval("4*5+2")) prints 22 while print(eval("04*5+2")) throws error. I'd really be grateful if someone can explain this to me!

Answer 1

you can not write 0 prefix because python use zero prefix to represent number type.

Number SystemPrefix
Binary '0b' or '0B'
Octal '0o' or '0O'
Hexadecimal '0x' or '0X'

use like below,
print(eval("0x4 * 5 + 2"))
print(eval("0b100 * 5 + 2"))
print(eval("0o4 * 5 + 2"))