Python program to print decimal octal hex and binary of first n numbers

Sometimes we need to display numbers in different formats: decimal, octal, hexadecimal, and binary. Python provides format specifiers to convert numbers into these representations with proper alignment.

So, if the input is like n = 10, then the output will be ?

1   1   1    1
2   2   2   10
3   3   3   11
4   4   4  100
5   5   5  101
6   6   6  110
7   7   7  111
8  10   8 1000
9  11   9 1001
10 12   A 1010

Understanding the Approach

The solution works by following these steps ?

• Calculate the width needed based on the binary representation of n
• For each number from 1 to n, format it in all four number systems
• Use format specifiers: 'd' for decimal, 'o' for octal, 'X' for hexadecimal, 'b' for binary
• Right-align each column for neat output

Complete Solution

def solve(n):
    # Calculate width based on binary representation of n
    width = len(bin(n)) - 2
    
    for i in range(1, n + 1):
        # Build format string for all four number systems
        format_str = ""
        for specifier in "doXb":
            if format_str:
                format_str += " "
            format_str += "{:>" + str(width) + specifier + "}"
        
        # Print formatted number in all four systems
        print(format_str.format(i, i, i, i))

# Test with n = 10
n = 10
solve(n)

1   1   1    1
2   2   2   10
3   3   3   11
4   4   4  100
5   5   5  101
6   6   6  110
7   7   7  111
8  10   8 1000
9  11   9 1001
10 12   A 1010

Alternative Approach Using Built-in Functions

You can also use Python's built-in functions for number conversion ?

def display_number_formats(n):
    # Calculate width for alignment
    width = len(bin(n)) - 2
    
    print(f"{'Decimal':<{width}} {'Octal':<{width}} {'Hex':<{width}} {'Binary':<{width}}")
    print("-" * (width * 4 + 3))
    
    for i in range(1, n + 1):
        decimal = str(i)
        octal = oct(i)[2:]  # Remove '0o' prefix
        hexadecimal = hex(i)[2:].upper()  # Remove '0x' prefix and convert to uppercase
        binary = bin(i)[2:]  # Remove '0b' prefix
        
        print(f"{decimal:>{width}} {octal:>{width}} {hexadecimal:>{width}} {binary:>{width}}")

# Test the function
display_number_formats(10)

Decimal Octal Hex Binary
-----------------
      1     1   1      1
      2     2   2     10
      3     3   3     11
      4     4   4    100
      5     5   5    101
      6     6   6    110
      7     7   7    111
      8    10   8   1000
      9    11   9   1001
     10    12   A   1010

How Format Specifiers Work

Conclusion

Python's format specifiers provide an elegant way to display numbers in different bases with proper alignment. The key is calculating the appropriate width and using right-alignment for neat columnar output.