Takes a profile file, a method name and depth, and shows you the chain of callers of the method

pstat-chain.py

import pstats
import re
import sys
from io import StringIO

"""
E.g.

python pstats-chain.py GET.foobar.com.testurl.46689ms.1597427246.prof 'time.sleep' 10

"""

pattern = re.compile(r"\/.*")
prof_file = sys.argv[1]
start_method = sys.argv[2]
max_depth = int(sys.argv[3])


class PstatsChainHandler:
    def __init__(self, prof_file, max_depth=5) -> None:
        self.prof_file = prof_file
        self.max_depth = max_depth
        self.depth_count = 0

    def find_caller(self, method):
        stream = StringIO()
        stats = pstats.Stats(self.prof_file, stream=stream)
        stats.sort_stats("time", "calls")

        stats.print_callers(method)

        lines = stream.getvalue().splitlines()

        if len(lines) < 6:
            print("there are no valid caller details")

        for caller in lines[5:-2]:
            try:
                _, caller_deets = caller.split("<-")
                matches = re.findall(pattern, caller_deets)
                if matches:
                    match = re.sub(r"\(\w+\)", "", matches[0])
                    print(match)
                    self.depth_count += 1
                    if self.depth_count <= self.max_depth:
                        self.find_caller(match)
            except ValueError:
                return


handler = PstatsChainHandler(prof_file=prof_file, max_depth=max_depth)
handler.find_caller(start_method)