pycfg-rs

Rust-based control flow graph generator for Python

This page shows the output of running pycfg-rs against 9 popular open-source Python projects. For each project, you can see analysis stats and the control flow graphs of the most complex functions — expand any function to view its CFG.

v0.1.0 commit 2da4c96 generated 2026-03-13 14:56 UTC
430
Python files
7,199
functions analyzed
943ms
total parse time
175
tests passing
9/9
projects passing

Projects

pytest 70 files 2,017 functions avg CC 2.6 239ms pass
70 files
2,017 functions
2.6 avg CC
28 max CC
8,446 fn/s
Complexity distribution: low (<5): 1703 moderate (5-9): 260 high (10-19): 51 very high (20+): 3

Top 5 most complex functions

RaisesGroup._check_exceptions CC 28
pytest/src/_pytest/raises.py:1266 53 blocks, 79 edges
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LocalPath.make_numbered_dir CC 24
pytest/src/_pytest/_py/path.py:1274 54 blocks, 76 edges
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Session.collect CC 24
pytest/src/_pytest/main.py:886 49 blocks, 71 edges
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LocalPath.pyimport CC 19
pytest/src/_pytest/_py/path.py:1070 41 blocks, 58 edges
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assertrepr_compare CC 19
pytest/src/_pytest/assertion/util.py:177 39 blocks, 56 edges
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pydantic 105 files 1,792 functions avg CC 2.9 267ms pass
105 files
1,792 functions
2.9 avg CC
51 max CC
6,723 fn/s
Complexity distribution: low (<5): 1503 moderate (5-9): 202 high (10-19): 74 very high (20+): 13

Top 5 most complex functions

traverse_schema CC 51
pydantic/pydantic/_internal/_schema_gather.py:89 104 blocks, 153 edges
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_apply_constraint CC 50
pydantic/pydantic/experimental/pipeline.py:442 101 blocks, 149 edges
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GenerateSchema.match_type CC 49
pydantic/pydantic/_internal/_generate_schema.py:1035 98 blocks, 145 edges
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ModelField._type_analysis CC 45
pydantic/pydantic/v1/fields.py:581 95 blocks, 138 edges
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ModelMetaclass.__new__ CC 31
pydantic/pydantic/v1/main.py:123 67 blocks, 96 edges
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rich 100 files 984 functions avg CC 2.5 122ms pass
100 files
984 functions
2.5 avg CC
36 max CC
8,082 fn/s
Complexity distribution: low (<5): 864 moderate (5-9): 86 high (10-19): 29 very high (20+): 5

Top 5 most complex functions

traverse._traverse CC 36
rich/rich/pretty.py:621 87 blocks, 121 edges
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Markdown.__rich_console__ CC 23
rich/rich/markdown.py:578 48 blocks, 69 edges
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Style.__str__ CC 21
rich/rich/style.py:290 42 blocks, 61 edges
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legacy_windows_render CC 20
rich/rich/_windows_renderer.py:6 42 blocks, 60 edges
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Table._render CC 20
rich/rich/table.py:755 44 blocks, 62 edges
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click 17 files 530 functions avg CC 2.7 85ms pass
17 files
530 functions
2.7 avg CC
33 max CC
6,236 fn/s
Complexity distribution: low (<5): 449 moderate (5-9): 64 high (10-19): 15 very high (20+): 2

Top 5 most complex functions

Option.__init__ CC 33
click/src/click/core.py:2709 69 blocks, 100 edges
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Option.get_help_extra CC 21
click/src/click/core.py:3033 49 blocks, 68 edges
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Command.main CC 17
click/src/click/core.py:1338 30 blocks, 45 edges
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open_url CC 16
click/src/click/_termui_impl.py:675 43 blocks, 57 edges
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Context.__init__ CC 16
click/src/click/core.py:273 34 blocks, 48 edges
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httpx 23 files 468 functions avg CC 2.2 37ms pass
23 files
468 functions
2.2 avg CC
17 max CC
12,640 fn/s
Complexity distribution: low (<5): 416 moderate (5-9): 50 high (10-19): 2 very high (20+): 0

Top 5 most complex functions

urlparse CC 17
httpx/httpx/_urlparse.py:212 32 blocks, 47 edges
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get_environment_proxies CC 10
httpx/httpx/_utils.py:29 21 blocks, 29 edges
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create_ssl_context CC 9
httpx/httpx/_config.py:22 21 blocks, 28 edges
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trace CC 9
httpx/httpx/_main.py:211 18 blocks, 25 edges
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URL.__init__ CC 9
httpx/httpx/_urls.py:77 19 blocks, 26 edges
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black 25 files 435 functions avg CC 4.4 92ms pass
25 files
435 functions
4.4 avg CC
84 max CC
4,753 fn/s
Complexity distribution: low (<5): 301 moderate (5-9): 91 high (10-19): 36 very high (20+): 7

Top 5 most complex functions

whitespace CC 84
black/src/black/nodes.py:179 162 blocks, 244 edges
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main CC 32
black/src/black/__init__.py:254 66 blocks, 96 edges
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get_features_used CC 32
black/src/black/__init__.py:1360 65 blocks, 95 edges
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normalize_invisible_parens CC 25
black/src/black/linegen.py:1475 51 blocks, 74 edges
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can_omit_invisible_parens CC 23
black/src/black/lines.py:938 45 blocks, 66 edges
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flask 24 files 407 functions avg CC 2.2 33ms pass
24 files
407 functions
2.2 avg CC
17 max CC
12,376 fn/s
Complexity distribution: low (<5): 366 moderate (5-9): 34 high (10-19): 7 very high (20+): 0

Top 5 most complex functions

Blueprint.register CC 17
flask/src/flask/sansio/blueprints.py:273 35 blocks, 50 edges
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Flask.make_response CC 14
flask/src/flask/app.py:1224 33 blocks, 45 edges
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Flask.run CC 11
flask/src/flask/app.py:632 28 blocks, 37 edges
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Flask.url_for CC 11
flask/src/flask/app.py:1102 26 blocks, 35 edges
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find_app_by_string CC 11
flask/src/flask/cli.py:119 28 blocks, 37 edges
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fastapi 48 files 315 functions avg CC 2.8 45ms pass
48 files
315 functions
2.8 avg CC
33 max CC
7,013 fn/s
Complexity distribution: low (<5): 272 moderate (5-9): 30 high (10-19): 6 very high (20+): 7

Top 5 most complex functions

get_openapi_path CC 33
fastapi/fastapi/openapi/utils.py:262 64 blocks, 95 edges
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analyze_param CC 32
fastapi/fastapi/dependencies/utils.py:389 52 blocks, 82 edges
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get_request_handler.app CC 28
fastapi/fastapi/routing.py:378 57 blocks, 83 edges
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jsonable_encoder CC 27
fastapi/fastapi/encoders.py:111 55 blocks, 80 edges
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get_openapi CC 24
fastapi/fastapi/openapi/utils.py:516 48 blocks, 70 edges
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requests 18 files 251 functions avg CC 2.8 25ms pass
18 files
251 functions
2.8 avg CC
18 max CC
10,115 fn/s
Complexity distribution: low (<5): 212 moderate (5-9): 27 high (10-19): 12 very high (20+): 0

Top 5 most complex functions

HTTPAdapter.send CC 18
requests/src/requests/adapters.py:592 37 blocks, 53 edges
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HTTPDigestAuth.build_digest_header CC 16
requests/src/requests/auth.py:126 35 blocks, 49 edges
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RequestEncodingMixin._encode_files CC 15
requests/src/requests/models.py:138 33 blocks, 46 edges
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PreparedRequest.prepare_url CC 15
requests/src/requests/models.py:411 34 blocks, 47 edges
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PreparedRequest.prepare_body CC 14
requests/src/requests/models.py:496 35 blocks, 47 edges
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