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Pyobfuscate
Dev Tools Module

Python Code to Flowchart — AST Flowchart & Control-Flow Graph Generator

Turn Python code into a flowchart from the real AST — deterministic, no AI. Handles if, match, loops, try/except and async, with a control-flow-graph mode, unreachable-code highlighting, and Mermaid/SVG/PNG export.

Why use this tool?

A flowchart is the fastest way to understand or explain what a piece of Python actually does — for students learning control flow, teachers building materials, or anyone documenting an unfamiliar function. This tool draws that flowchart directly from your code so the diagram always matches the logic, instead of being hand-drawn and going stale.

The difference from AI-based generators is determinism. This tool parses your code with Python's own Abstract Syntax Tree (the `ast` module), so the same input always yields the same diagram and every branch is grounded in the real structure — not a language model's best guess. It understands modern Python properly: `if`/`elif`/`else`, `match`/`case`, `for`/`while` loops with `break`/`continue`, `try`/`except`/`finally`, `with`, and `async`/`await`.

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Python Source Code
def classify(items):
    total = 0
    for x in items:
        if x < 0:
            continue
        total += x
    if total > 100:
        return "large"
    elif total > 0:
        return "small"
    return "empty"
Diagram
Your flowchart appears here. It's built from Python's real AST — deterministic, no AI guessing — with proper if / match / loop / try / async handling.

Tool facts

Supported Python
Python 3.x source (parsed with CPython's ast)
Input limit
Limited only by your device
Last reviewed
2026-08-25

What it can't do

  • •Diagram code that has a syntax error — it reports the exact line and column so you can fix it first.
  • •Trace runtime values or which branch actually executes — it's static control flow, not a debugger.
  • •Expand third-party functions you call — each call is shown as a single step, not inlined.

About Code to Flowchart

The Code-to-Flowchart tool converts Python source into a visual diagram of its control flow. Your code is parsed with CPython's ast module (via WebAssembly) in your browser, walked statement by statement, and rendered as a Mermaid diagram.

Two views are available. **Flowchart** mode shows every statement as its own node, with diamond decision nodes for if, while, and match, so it reads like a classic flow diagram. **Control-flow graph** mode collapses straight-line runs of statements into basic blocks and only splits at branches and joins — the compact representation compilers and static analyzers use. You can switch between the whole program and any individual function with the scope selector, which is useful for large files where a single mega-chart would be unreadable.

It also highlights **unreachable code**: any statement that can never run — for example, code after an unconditional return, raise, break, or continue — is drawn dashed and red and called out above the diagram with its line number. That makes the tool a quick static check as well as a visualization.

When you're happy with a diagram you can copy the underlying **Mermaid** text (to embed in Markdown, GitHub, or docs), download a crisp **SVG** or a 2× **PNG**, or copy a **share link** that encodes the source in the URL so a teammate opens the exact same chart. Because the whole thing is client-side and deterministic, it's well suited to classrooms, code review, and documentation where you need the picture to be an accurate, reproducible reflection of the code.

Prefer to see the raw tree instead of the flow? Try the Python AST viewer; to step through bytecode, see the bytecode disassembler; and to check types before runtime, use the Python type checker.

Frequently Asked Questions

It doesn't use AI. It parses your code with Python's real Abstract Syntax Tree (the ast module), so the flowchart is a deterministic, exact reflection of your code's structure — the same input always produces the same diagram, and no branch is invented or missed. AI tools can hallucinate or miss edge cases; an AST-based tool cannot.

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