Add one to binary string

[uwl]

I have a string with the value '0101', it is a binary number. I wish to add one bit to it in order to obtain '0110'. Is someone able to help me accomplish this in my python program.

bit_s = '1010'
inverse_s = '' #add one bit
#two_s = ''  two's comp
for i in bit_s:
	if i == '0':
		inverse_s += '1'	
	else:
		inverse_s += '0'	
print("Inversed string is ",
	inverse_s) #tried + '1' bad output

[deanhystad]

Convert it to an int?

If this is a homework assignment, and you need to do the addition using the binary string, 1+1 = 0, carry the 1. You don't have a carry in you code.

I think it would also be easer working left to right instead of right to left. I would start by reversing the string "1010" to "0101", then I would do the addition, and finally I would reverse the string back.

Output:
1010 + 1
Reverse the strings
 0101
+1

Do the addition
0+1 = 1
1+_ = 1
0+_ = 0
1+_ = 1
1101

Reverse the result
1011

If there is a carry

Output:
1010 + 10
Reverse the strings
 0101
+01

Do the addition
0+0 = 0
1+1 = 0, carry = 1
0+_+carry = 1
1+_ = 1
0011

Reverse the result
1100

[uwl]

I mean I do not know how to code logic of each index position of my string has to be added 1 bit or become 0 if it is already 1. You may be right how I need to use a carry.

bit_s = '1010'
inverse_s = ''
two_s = ''
int carry = 0
for i in bit_s:
    if i == '0':
        inverse_s += '1'    
    else:
        inverse_s += '0'

#logic

print(two_s)