In any programming task, you often come across a situation where it is necessary to extract certain digits from a string. In Python, this is a rather straightforward operation that can be achieved with the use of regular expressions.
Regular expressions are a special sequence of characters that helps you match or find other strings or sets of strings, using a specialized syntax. In Python, the re module provides support for regular expressions. Today, we are going to teach you how to find digits in a string using Python.
Step 1: Import the re module
To work with regular expressions in Python, we must import the re module. To import the re module, just type this line at the start of your script:
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import re |
Step 2: Define the string
Next, you will need to define the string from which you want to extract the digits. For example:
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string = "There are 12 months in a year, 7 days in a week." |
Step 3: Use the findall() method
The re.findall() method returns all non-overlapping matches of a pattern in string, as a list of strings. By passing the pattern and string to this method, we can extract all digits found in the string.
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digits = re.findall('\d+', string) |
Here, ‘\d+’ is the pattern that matches any digit (0-9).
Step 4: Print the digits
Finally, print the digits to the console:
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print(digits) |
Here is the full code:
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import re string = "There are 12 months in a year, 7 days in a week." digits = re.findall('\d+', string) print(digits) |
Output:
['12', '7']
This program will output all the digits in the string as elements of an array.
Conclusion
By learning how to use regular expressions with the re module in Python, you can easily extract digits from a string. This is an important skill since it can save a lot of time and coding effort when parsing and sanitizing input or processing text data for information extraction.