Source code for tradeexecutor.utils.python_function

"""Python function utilities.

- Hash Python function bodies


import ast
import hashlib
import inspect
import textwrap

def _remove_docstring(node):
    Removes all the doc strings in a FunctionDef or ClassDef as node.
        node (ast.FunctionDef or ast.ClassDef): The node whose docstrings to
    if not (isinstance(node, ast.FunctionDef) or
            isinstance(node, ast.ClassDef)):

    if len(node.body) != 0:
        docstr = node.body[0]
        if isinstance(docstr, ast.Expr) and isinstance(docstr.value, ast.Str):

[docs]def hash_function(func, char_length=8, bytecode_only=False): """Produces a hash for the code in the given function. See Hash is not guaranteed to be the same across different environments / scenarios. Read the function for more info. :param char_length: How many characters you want in your hash, to reduce the hash size. :param bytecode_only: Don't attempt to hash with sanitised source. We will also autodetect this when the source is not available. :return: Part of hex hash of the function body """ assert callable(func), f"Not a function: {func}" try: func_str = inspect.getsource(func) except OSError: # When using with multiprocessing. # Fall back to function bytecode # File "/Users/moo/.pyenv/versions/3.11.5/lib/python3.11/", line 1081, in findsource # raise OSError('could not get source code') bytecode_only = True if not bytecode_only: func_str = textwrap.dedent(func_str) # Heurestics if this is a lambda function - in this case ast will fail # Account for ending new line (may or may not be there?) lambda_like = len(func_str.split("\n")) in (1, 2) and "lambda" in func_str if not lambda_like: module = ast.parse(func_str) assert len(module.body) == 1 and isinstance(module.body[0], ast.FunctionDef) # Clear function name so it doesn't affect the hash func_node = module.body[0] = "" # Clear all the doc strings for node in ast.walk(module): _remove_docstring(node) # Convert the ast to a string for hashing ast_str = ast.dump(module, annotate_fields=False).encode("utf-8") # Produce the hash fhash = hashlib.sha256(ast_str) else: # Handle lambda special case fhash = hashlib.sha256(func_str.encode("utf-8")) else: fhash = hashlib.sha256(func.__code__.co_code) return fhash.hexdigest()[0:char_length]