How To Find First Number In Python

Finding the first number in Python can be helpful when you’re working with arrays or lists that contain numeric values. In this tutorial, we’ll discuss how to find the first number in Python using a few different methods.

Using the for Loop

One of the simplest ways to find the first number in Python is to use a for loop to iterate through a list or array. Here’s an example code snippet to get you started:

1
2
3
4
5
6
my_list = [5, 10, 15, 20, 25]
 
for num in my_list:
   if isinstance(num, (int, float)):
     print("The first number is: ", num)
     break

Explanation:

The above code snippet works by first creating a list containing some numbers. The for loop is used to iterate through each item in the list. Inside the loop, the isinstance function is used to check if the current item is a numeric value (either an integer or a float). If the item is numeric, the print message displays the item and the loop is terminated using the ‘break’ statement.

Using Regular Expressions

Another way to find the first number in Python is by using regular expressions. Regular expressions are a powerful way to search for patterns in text data.

Here’s an example code snippet that uses a regular expression to find the first number in a given string:

1
2
3
4
5
6
7
import re
 
my_string = "Hello, 123 World!"
match = re.search(r'\d+', my_string)
 
if match:
    print("The first number is: ", match.group())

Explanation:

The above code uses the re module to search for a numeric pattern in a string. The regular expression ‘\d+’ matches one or more digits.

The search function is used to find the first occurrence of this pattern in the input string. If a match is found, the group function is called to extract the matching text.

Conclusion

In this tutorial, we’ve covered two different methods for finding the first number in Python: using a simple for loop and using regular expressions. Both methods can be useful depending on the type of data you’re working with.

1
2
3
4
5
6
my_list = [5, 'hello', 10, None, 15, 20.5, 'world', 25.3]
 
for num in my_list:
    if isinstance(num, (int, float)):
        print("The first number is: ", num)
        break

Output:

The first number is: 5