littlest_coverage.py

import sys

lines = {}

def start():
    sys.settrace(trace)

def stop():
    sys.settrace(None)
    for filename in lines:
        if filename.startswith('./'):
            print(filename, len(lines[filename]) / count_lines(filename))

def count_lines(filename):
    try:
        return len(list(open(filename)))
    except FileNotFoundError:
        return 0

def trace(frame, event, arg):
    if event == 'line':
        filename = frame.f_code.co_filename
        lineno = frame.f_lineno
        lines.setdefault(filename, set()).add(lineno)
    elif event == 'call':
        return trace

littlest_debugger.py

import sys


def getch():
    return sys.stdin.read(1)

def start():
    sys.settrace(trace)

def stop():
    sys.settrace(None)

def trace(frame, event, arg):
    try:
        line = list(open(frame.f_code.co_filename))[frame.f_lineno - 1].strip()
    except NameError:
        line = None
    if line is not None:
        if event == 'line':
            print(f'{frame.f_code.co_filename}:{frame.f_lineno} {line}')
            getch()
        elif event == 'call':
            print(f'step in? {frame.f_code.co_filename}:{frame.f_lineno} {line}')
            if getch() == 's':
                return trace

littlest_profiler.py

import sys, time


call_stack = []
call_times = []

calltime_accum = {}


def start():
    sys.settrace(trace)

def stop():
    sys.settrace(None)
    times = list(calltime_accum.items())
    times.sort(key=lambda e: e[1])
    for func, t in times:
        print(func, t)

def trace(frame, event, arg):
    try:
        line = list(open(frame.f_code.co_filename))[frame.f_lineno - 1].strip()
    except (NameError, FileNotFoundError):
        line = None
    if line is not None:
        if event == 'call':
            func_name = line.split('def ')[1].split('(')[0]
            func = f'{frame.f_code.co_filename}:{func_name}'
            call_stack.append(func)
            call_times.append(time.time())
            return trace
        elif event == 'return':
            func = call_stack.pop()
            start = call_times.pop()
            end = time.time()
            t = end - start
            calltime_accum.setdefault(func, 0)
            calltime_accum[func] += t

littlest_tracer.py

import sys

def start():
    sys.settrace(trace)

def stop():
    sys.settrace(None)

def trace(frame, event, arg):
    if event == 'line':
        line = list(open(frame.f_code.co_filename))[frame.f_lineno - 1].strip()
        print(f'{frame.f_code.co_filename}:{frame.f_lineno} {line}')
    elif event == 'call':
        return trace

test.py

#!/usr/bin/env python3
# Usage: ./test.py littlest_{module}
import sys
exec(f'import {sys.argv[1]}')

def incr(x):
  x = x + 1
  return x

def foo():
  x = 1 + 2
  x = incr(x)
  print('Hello, World!')

def baz():
  x = 1 + 2
  for i in range(10):
    x = incr(x)
  return x

exec(f'{sys.argv[1]}.start()')
foo()
y = baz()
print('Final Result:', y)
exec(f'{sys.argv[1]}.stop()')

these are neat!