如何将列表中的整数合并为单个整数？现有代码无法实现需求寻求解决办法

Hey there! Let's get your code working to turn that list of integers into one combined number.

What's Wrong with Your Current Code? #

Your original approach converts the entire list to a string (which gives something like "[1, 2, 3, 4, 5, 6]"), splits it, and filters for digits. While this extracts the individual numbers, it leaves you with another list of integers—instead of merging them into one single integer.

Solution 1: String Concatenation (Simple & Intuitive) #

This method converts each integer to a string, joins them all together, then converts back to an integer:

l1 = [1,2,3,4,5]
merged_num = int(''.join(str(num) for num in l1))
print(merged_num)  # Output: 12345

• str(num): Converts each integer in the list to a string (e.g., 1 → "1").
• ''.join(...): Joins all these string digits into one continuous string (e.g., "1"+"2"+"3"+"4"+"5" → "12345").
• int(...): Converts the concatenated string back to an integer.

Solution 2: Mathematical Calculation (No String Operations) #

If you prefer to avoid string conversions, you can build the number using arithmetic:

l1 = [1,2,3,4,5]
merged_num = 0
for num in l1:
    merged_num = merged_num * 10 + num
print(merged_num)  # Output: 12345

• How it works: For each number, we shift the current result left by one digit (multiply by 10) and add the new number. For example:
  • Start with 0 → 0*10 +1 =1
  • Next: 1*10 +2=12
  • Continue until we get 12345.

Both methods will work perfectly for your use case. The string method is shorter and easier to read, while the math method is great if you want to stick to numerical operations.

内容的提问来源于stack exchange，提问作者ahmed_elghoroury