Convert a list of multiple integers into a single integer in Python

Sometimes we may have a list whose elements are integers. There may be a need to combine all these elements and create a single integer out of it. In this article we will explore the ways to do that.

Using List Comprehension with join()

The join() method can join all items in a list into a string. We use list comprehension to convert each integer to a string, then join them together ?

Example

numbers = [22, 11, 34]

# Given list
print("Given list:", numbers)

# Convert each integer to string and join them
result = int("".join([str(i) for i in numbers]))

# Result
print("The integer is:", result)

The output of the above code is ?

Given list: [22, 11, 34]
The integer is: 221134

Using map() with join()

We can apply the map() function to convert each element of the list into a string and then join each of them to form a final string. Applying the int() function makes the final result an integer ?

Example

numbers = [22, 11, 34]

# Given list
print("Given list:", numbers)

# Use map to convert integers to strings, then join
result = int("".join(map(str, numbers)))

# Result
print("The integer is:", result)

The output of the above code is ?

Given list: [22, 11, 34]
The integer is: 221134

Using String Formatting

Another approach is to use string formatting to concatenate the integers directly ?

Example

numbers = [22, 11, 34]

# Given list
print("Given list:", numbers)

# Use string formatting to concatenate
result = int(''.join(f'{num}' for num in numbers))

# Result
print("The integer is:", result)

The output of the above code is ?

Given list: [22, 11, 34]
The integer is: 221134

Comparison

Conclusion

All three methods effectively convert a list of integers into a single integer by concatenation. The map() approach is generally the most efficient, while string formatting offers the cleanest syntax for modern Python code.