Basic Python profiler

profile.py

from contextlib import contextmanager
from timeit import default_timer as timer
try:
    import matplotlib
except ModuleNotFoundError:
    PLOT = False
else:
    PLOT = True

class Profiler:

    def __init__(self, name):
        self.name = name
        self.profiles = {}

    @contextmanager
    def scope(self, name):
        start = timer()
        try:
            yield None
        finally:
            interval = timer() - start
            self.profiles.setdefault(name, 0.0)
            self.profiles[name] += interval

    def plot(self):
        if not PLOT:
            raise ModuleNotFoundError("Module matplotlib is required for plotting but is not found.")

    def log(self):
        items = self.profiles.items()
        items = sorted(items, key = lambda i: i[1], reverse = True)
        for name, time in items:
            print(f"{name}:\t{time}")


profiler = Profiler("my_profiler")
for i in range(10000):
    with profiler.scope("sum"):
        1 + 1
for i in range(100000):
    with profiler.scope("sub"):
        1 - 1
profiler.log()