count lines of code in a project

count_lines.py

# Counting lines of code in a project
# Usage: python3 count_lines.py /path/to/project/src .cpp .h .py
# (if no extensions are specified, will count across all files)

import os
from collections import defaultdict

line_filters = {}
for ext in ('java', 'cpp', 'cc', 'cxx', 'c', 'h', 'hpp'):
    line_filters[ext] = lambda line: line.strip().endswith(b';')

line_counts = defaultdict(lambda: 0)

def count_lines_in_file(path, extensions=None):
    filename, extension = os.path.splitext(path)
    line_filter = line_filters.get(extension, lambda line:not line.isspace())
    if extensions and extension not in extensions:
        return
    with open(path, 'rb') as f:
        for line in f:
            if line_filter(line):
                line_counts[extension] += 1


if __name__ == '__main__':
    import sys
    if len(sys.argv) > 1:
        project_dir = sys.argv[1]
    else:
        project_dir = '.'

    if len(sys.argv) > 2:
        extensions = sys.argv[2:]
    else:
        extensions = None

    for r,d,f in os.walk(project_dir):
        for filename in f:
            path = os.path.join(r, filename)
            count_lines_in_file(path, extensions)

    total_lines = 0
    for ext, nlines in line_counts.items():
        total_lines += nlines
        print('{0}: {1}'.format(ext, nlines))
    print('total: {0}'.format(total_lines))