How to Parse a Comma String into a List of Integers in Python

Converts a comma-separated string into a list of integers, handling spaces and empty inputs.

Easy Python 3.9+ Aug 9, 2026 Lists & loops 13 views 0 copies

csv parsing list-comprehension integers

Python code

10 lines

Python 3.9+

def parse_csv_to_ints(text: str) -> list[int]:
    """Parse a comma-separated string into a list of integers."""
    if not text.strip():
        return []
    return [int(part.strip()) for part in text.split(",") if part.strip()]

if __name__ == "__main__":
    sample = "10, 20, 30, 40, 50"
    result = parse_csv_to_ints(sample)
    print(result)

Output

stdout

[10, 20, 30, 40, 50]

How it works

The split(",") method separates the string at each comma, producing a list of substrings. A list comprehension then strips whitespace from each part with .strip() and converts it to an integer with int(). The if part.strip() condition filters out empty strings, which would otherwise cause a ValueError. For empty or whitespace-only input, the function returns an empty list upfront to avoid issues. This pattern is concise, readable, and robust for typical CSV-like data.

Common mistakes

Forgetting to strip whitespace, causing `int(' 10')` to fail with a ValueError.
Not filtering empty strings, which leads to errors when input has trailing commas.
Assuming input is always valid, without handling non-numeric parts gracefully.

Variations

Use `map(int, text.split(','))` if the input has no spaces and no empty parts.
Use a try/except block to skip or handle invalid values instead of failing.

Real-world use cases

Parsing configuration values like port lists from environment variables.
Reading user input in a CLI tool that accepts comma-separated IDs.
Extracting numeric tokens from log data or CSV snippets in an ETL pipeline.

How to Parse a Comma String into a List of Integers in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

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