str_number = "123"
int_number = int(str_number)
print(int_number)
str_number = "123.45"
float_number = float(str_number)
print(float_number)
str_number = "123"
int_number = 0
for char in str_number:
int_number = int_number * 10 + int(char)
print(int_number)
import re
str_number = "123abc"
int_number = int(re.search(r'\d+', str_number).group())
print(int_number)
