Python program to find all close matches of input string from a list

In this tutorial, we will find all strings from a list that closely match a given input string. A close match means either the string starts with the input element or the input element starts with the string.

Problem Statement

Given a list of strings and an input element, find all strings that have a close match with the element ?

Input:
strings = ["Lion", "Li", "Tiger", "Tig"] 
element = "Lion"

Output:
Lion Li

Algorithm

We can solve this using the startswith() method with the following steps ?

• Initialize the string list and input element
• Loop through each string in the list
• Check if the string starts with the element OR the element starts with the string
• If either condition is true, include it in the result

Example

# Initialize the string list and element
strings = ["Lion", "Li", "Tiger", "Tig"]
element = "Lion"

print("Close matches:")
for string in strings:
    # Check if string starts with element or element starts with string
    if string.startswith(element) or element.startswith(string):
        print(string, end=" ")
print()  # New line after results

Close matches:
Lion Li 

How It Works

The condition string.startswith(element) or element.startswith(string) checks two cases ?

• "Lion".startswith("Lion") ? True (exact match)
• "Li".startswith("Lion") ? False, but "Lion".startswith("Li") ? True
• "Tiger".startswith("Lion") ? False, and "Lion".startswith("Tiger") ? False

Alternative Approach Using List Comprehension

strings = ["Lion", "Li", "Tiger", "Tig"]
element = "Lion"

# Using list comprehension
close_matches = [s for s in strings if s.startswith(element) or element.startswith(s)]
print("Close matches:", " ".join(close_matches))

Close matches: Lion Li

Complete Function Implementation

def find_close_matches(strings, element):
    """Find all strings that closely match the given element"""
    matches = []
    for string in strings:
        if string.startswith(element) or element.startswith(string):
            matches.append(string)
    return matches

# Test the function
strings = ["Lion", "Li", "Tiger", "Tig", "Python", "Py"]
element = "Lion"

result = find_close_matches(strings, element)
print(f"Close matches for '{element}': {result}")

# Test with different element
element2 = "Py"
result2 = find_close_matches(strings, element2)
print(f"Close matches for '{element2}': {result2}")

Close matches for 'Lion': ['Lion', 'Li']
Close matches for 'Py': ['Python', 'Py']

Conclusion

Use the startswith() method to find close matches by checking if strings start with each other. This approach works well for prefix-based matching and can be implemented using loops or list comprehension.