如何整齐打印邻接矩阵的列索引以提升矩阵可读性？

Hey, let's fix that messy column header alignment for your adjacency matrix! The issue right now is that printing column labels as a raw list doesn't account for varying digit lengths (like 1 vs. 12) and the default list formatting adds brackets/commas that throw off alignment. Here's a straightforward approach to get clean, perfectly aligned output:

Core Ideas to Fix Alignment #

• Use a fixed width for all indices: First, calculate how many digits your largest vertex number has (e.g., if your vertices go up to 20, that's 2 digits). This becomes the standard width for every row and column label, so they all line up neatly.
• Format column headers as a single aligned string: Ditch the raw list print. Instead, format each column number to the fixed width, then join them with spaces—this removes messy brackets and ensures consistent spacing.
• Simplify row index printing: Replace your if/else check with a formatted string that automatically aligns row indices to the same fixed width as columns.

Modified Code with Clean Alignment #

def generate_adjacency_matrix(vertices):
    size = len(vertices)
    # Create empty adjacency matrix
    matrix = [['.' for _ in range(size)] for _ in range(size)]
    
    # Fill matrix with connections (simplified loop)
    for row in vertices:
        for connected_vertex in vertices[row]:
            matrix[row][connected_vertex] = '1'
    
    # Calculate fixed width for all index labels
    max_width = len(str(size - 1))
    
    # Print aligned column headers
    col_headers = [f"{num:>{max_width}}" for num in range(size)]
    print(' ' * max_width, ' '.join(col_headers))
    
    # Print matrix with aligned row indices
    for i in range(size):
        print(f"{i:>{max_width}} {matrix[i]}")

Key Improvements Explained #

1. Simplified matrix filling: Instead of looping through every column to check for connections, we directly iterate over the connected vertices in your input dictionary—this is more efficient and cleaner.
2. Uniform index width: max_width ensures every label (whether 1-digit like 0 or 2-digit like 12) takes up the same amount of space. The :>{max_width} format specifier right-aligns numbers, which looks natural for indices.
3. Clean column headers: By joining formatted labels with spaces, we eliminate the list brackets and commas that were causing misalignment. The leading ' ' * max_width ensures the column headers line up perfectly with the row indices below.

Example Output Preview #

For your input dictionary including vertex 20, the output will look something like this:

0  1  2  3  ... 20
 0 ['1', '.', '.', '.', ..., '.']
 1 ['.', '.', '.', '.', ..., '.']
...
20 ['.', '.', '.', '.', ..., '.']

内容的提问来源于stack exchange，提问作者Neistow