Check if the given decimal number has 0 and 1 digits only in Python

Sometimes we need to check if a decimal number contains only binary digits (0 and 1). This is useful for validating binary representations or checking if a number can be interpreted as a binary string.

So, if the input is like num = 101101, then the output will be True since it contains only 0s and 1s.

Algorithm

To solve this, we will follow these steps −

• Extract all digits from the number into a set
• Remove 0 and 1 from the digits set
• If the set is empty after removal, return True
• Otherwise, return False

Using Set Operations

We can extract digits, store them in a set, and check if only 0 and 1 remain ?

def solve(num):
    digits_set = set()
    
    while num > 0:
        digit = num % 10
        digits_set.add(digit)
        num = int(num / 10)
    
    digits_set.discard(0)
    digits_set.discard(1)
    
    if len(digits_set) == 0:
        return True
    return False

# Test the function
num = 101101
print(f"Number: {num}")
print(f"Contains only 0s and 1s: {solve(num)}")

# Test with other numbers
test_cases = [101101, 1010, 123, 1111, 10203]
for test_num in test_cases:
    print(f"{test_num}: {solve(test_num)}")

Number: 101101
Contains only 0s and 1s: True
101101: True
1010: True
123: False
1111: True
10203: False

Using String Conversion Method

A simpler approach is to convert the number to string and check each character ?

def check_binary_digits(num):
    num_str = str(num)
    for char in num_str:
        if char not in ['0', '1']:
            return False
    return True

# Test the function
test_numbers = [101101, 1010, 123, 1111, 10203, 0, 1]
for num in test_numbers:
    result = check_binary_digits(num)
    print(f"{num}: {result}")

101101: True
1010: True
123: False
1111: True
10203: False
0: True
1: True

Using Set Comparison

We can also use set operations to check if all digits are subset of {0, 1} ?

def is_binary_number(num):
    digits = set(str(num))
    binary_digits = {'0', '1'}
    return digits.issubset(binary_digits)

# Test the function
numbers = [101101, 1010, 123, 1111, 10203]
for num in numbers:
    result = is_binary_number(num)
    print(f"{num} contains only 0s and 1s: {result}")

101101 contains only 0s and 1s: True
1010 contains only 0s and 1s: True
123 contains only 0s and 1s: False
1111 contains only 0s and 1s: True
10203 contains only 0s and 1s: False

Comparison

Conclusion

All three methods effectively check if a number contains only 0 and 1 digits. The string conversion method is most readable, while set comparison provides the most concise solution. Choose based on your preference for readability versus brevity.