Hooking all Python imports to print the increase in pages and memory size (Linux only, Python 3.7 tested)

importmon.py

import sys
import importlib

class ImportInterceptor(importlib.abc.Loader):
    def __init__(self):
        pass

    def find_module(self, fullname, path=None):
        #sys.stderr.write("LOAD INFO: %s\n" % (fullname))
        return self

    def load_module(self, fullname):
        with open('/proc/self/statm') as fp:
            before = int(fp.readline().split(" ")[0])

        sys.meta_path = [x for x in sys.meta_path[1:] if x is not self]
        module = importlib.import_module(fullname)

        with open('/proc/self/statm') as fp:
            after = int(fp.readline().split(" ")[0])

        delta = after-before
        delta_kb = delta*4096/1024
        total_kb = after*4096/1024

        sys.stderr.write("LOAD: %s (+%d pages, %d kB, total %d %d kB)\n" % (
            fullname, delta, delta_kb, after, total_kb))
        sys.stderr.flush()

        sys.meta_path = [self] + sys.meta_path
        return module

before = 0

if not hasattr(sys,'frozen'):
    importer = ImportInterceptor()
    sys.meta_path = [importer] + sys.meta_path

    def PathCaller(path):
        global before

        with open('/proc/self/statm') as fp:
            after = int(fp.readline().split(" ")[0])

        delta = after-before
        delta_kb = delta*4096/1024
        total_kb = after*4096/1024
        sys.stderr.write("LOAD: %s (+%d pages, %d kB, total %d %d kB)\n" % (
            path, delta, delta_kb, after, total_kb))
        sys.stderr.flush()

        before = after
        return sys.path_hooks[1](path)

    sys.path_hooks = [PathCaller] + sys.path_hooks

    print("Monitoring imports...")

usage.py

#!/usr/bin/env python3
# always import before anything else
import importmon
import sys
import os
# plus any other imports you want...