# Python - Check if a given string is binary string or not

In this article we check if a given string has characters which are only 1 or 0. We call such strings as binary strings. If it has any other digit like 2 or 3 etc., we classify it as a non-binary string.

## With set

The set operator in python stores only unique elements. So we take a string and apply the set function to it. Then we create another set which has only 0 and 1 as its elements. If both these sets are equal then the string is definitely binary. Also the string may have only 1s or only 0s. So we create a or condition which will also compare the result of set operator only with 0 or only with 1.

## Example

Live Demo

stringA = '0110101010111'
b = {'0','1'}
t = set(stringA)

if b == t or t == {'0'} or t == {'1'}:
print("StringA is a binary string.")
else:
print("StringA is not a binary string.")

stringB = '0120101010111'
u = set(stringB)

if b == u or u == {'0'} or u == {'1'}:
print("StringB is a binary string.")
else:
print("StringB is not a binary string.")

## Output

Running the above code gives us the following result −

StringA is a binary string.
StringB is not a binary string.

## With simple iteration

We can first declare a string with value as 01 or 10. Then compare the chraracters of this string with the characters of the given string. If the

## Example

Live Demo

stringA = "01100000001"

b = '10'
count = 0
for char in stringA:
if char not in b:
count = 1
break
else:
pass
if count:
print("StringA is not a binary string")
else:
print("StringA is a binary string")

stringB = "01200000001"
for char in stringB:
if char not in b:
count = 1
break
else:
pass
if count:
print("StringB is not a binary string")
else:
print("StringB is a binary string")

## Output

Running the above code gives us the following result −

StringA is a binary string
StringB is not a binary string