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PYTHON PROGRAM • LISTS

Flatten a Nested List in Python

Learn flatten a nested list in python with a short, executable Python example.

BeginnerNested comprehensionMatrix

PROBLEM UNDERSTANDING

Input and expected output

Sample input
No input required
Sample output
[1, 2, 3, 4, 5, 6]

COMPLETE PYTHON PROGRAM

Complete Python implementation

python-flatten-matrix.py
Open in compiler
matrix = [[1, 2], [3, 4], [5, 6]]
flat = [value for row in matrix for value in row]
print(flat)

GUIDED CODE TOUR • NOT LIVE EXECUTION

Study the program line by line

Use the real compiler button above to run and debug with different inputs.

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

[1, 2, 3, 4, 5, 6]
0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

  1. Initialize the sample values used to flatten a nested list.
  2. Process the data step by step using Nested comprehension and Matrix.
  3. Display the result for flatten a nested list and compare it with the documented sample output.

This example of flatten a nested list processes the sample values in a controlled iteration. It demonstrates Nested comprehension and Matrix and prints a deterministic result that can be checked against the sample output.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(n)

DEBUGGING CHECKLIST

Common mistakes

Check this

For flatten a nested list, keep the data shape and value types consistent with Nested comprehension.

Check this

Keep every dependent statement inside the correct indented Python block.

Check this

Verify the final Nested comprehension and Matrix result against the sample before trying new data.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.