Remove everything in a string which is not a number
Solution
def main():
raw_string = input('Enter a string: ')
num_string = just_number(raw_string)
print(num_string)
def just_number(str):
'''
Takes a string and returns a reversed copy
>>> just_number('My phone number is 6508675309. Please call!')
'6508675309'
>>> just_number('abc123def456')
'123456'
'''
curr_str = ''
for ch in str:
if ch.isdigit():
curr_str += ch
return curr_str
if __name__ == '__main__':
main()