Open
Description
Bug report
inspect.getmodule
is slow. It becomes slower as len(sys.modules)
grows. It is slower with modules that don't resolve to valid file paths. This causes inspect.stack
and others to be slow as well.
def run_test(module):
# cols have stack depths
# rows have len(sys.modules)
def print_line(h, *vals):
if not h:
print("%5s" % h, *["%6i" % v for v in vals])
else:
print("%5s" % h, *["%6.1f" % v for v in vals])
def add_modules(n):
import random
import sys
for _ in range(n):
sys.modules[f"foo_{random.randint(0,2**64)}"] = module
def measure(depth):
import inspect
import timeit
def nest(level):
if level > 0:
return nest(level-1)
else:
dur = timeit.timeit(lambda: inspect.stack(), number=1)
return dur * 1000
return nest(depth)
import sys
print_line("", *[2**e for e in range(7)])
for i in range(1, 5):
add_modules(n=10**i)
times = [measure(depth=2**e) for e in range(7)]
print_line(len(sys.modules), *times)
python 3.11.0a7+ optimized build ====
# sys has no __file__ and doesn't enter getmodule cache
>>> import sys
>>> run_test(sys)
1 2 4 8 16 32 64
87 2.1 0.8 1.0 1.3 2.0 3.3 6.1
187 2.0 2.5 2.7 3.6 5.5 9.5 16.8
1187 13.6 15.7 19.1 26.3 39.6 67.4 123.3
11187 134.1 150.3 183.4 252.0 383.5 750.3 1189.8
>>> exit()
>>> import random
>>> run_test(random)
1 2 4 8 16 32 64
87 2.1 0.7 0.9 1.2 1.7 2.9 5.6
187 2.3 1.1 1.5 1.8 2.5 4.3 7.8
1187 17.0 4.3 5.6 7.1 11.1 18.6 33.9
11187 164.6 37.4 45.7 61.6 94.7 161.0 297.7
>>> exit()
Tables show time in milliseconds for a single inspect.stack()
call.
Rows show len(sys.modules)
Columns indicate stack depth
Your environment
- CPython versions tested on: 3.9, 3.11.0a7+
- Operating system and architecture: MacOS, Linux, x64