Detect which lines can be removed from a .py file without breaking tests

coverage_but_not_quite.py

import subprocess

path = "hc/api/views.py"
test_cmd = "python manage.py test --keepdb --parallel=8 -v 0"

original = open(path, "r").read()
report = open("report-%s.txt" % path.replace("/", "."), "w")

lines = original.split("\n")
for idx in range(0, len(lines)):
    print("Processing %d / %d" % (idx, len(lines)))

    # Optimization: skip empty lines and comments
    if not lines[idx].strip() or lines[idx].strip().startswith("#"):
        report.write("  %s\n" % lines[idx])
        continue

    ll = lines[:idx] + lines[idx + 1 :]

    with open(path, "w") as f:
        f.write("\n".join(ll))

    flag = " " if subprocess.call(test_cmd, shell=True) else "-"
    report.write("%s %s\n" % (flag, lines[idx]))


# Restore original:
with open(path, "w") as f:
    f.write(original)

report.close()