求助：TypeError报错解决——'builtin_function_or_method'对象不可迭代

Let's break down what's causing this error and how to fix it.

The Problem #

You're hitting this error because the values parameter being passed to your _asarray_tuplesafe function is a builtin function or method object (not an iterable sequence like a list, tuple, or Pandas Index). When the code tries to convert this function object to a list with values = list(values), it fails because function objects aren't iterable.

Here's your original code for reference:

def _asarray_tuplesafe(values, dtype=None):
    from pandas.core.index import Index
    if not (isinstance(values, (list, tuple)) or hasattr(values, '__array__')):
        values = list(values)
    elif isinstance(values, Index):
        return values.values

And the error you're seeing:

第379行，位于_asarray_tuplesafe函数中，values = list(values)
TypeError: 'builtin_function_or_method' object is not iterable

Solutions #

1. Fix the function call (most critical step) #

First, check where you're calling _asarray_tuplesafe—you're probably passing a function/method instead of its result. For example:

• ❌ Wrong: _asarray_tuplesafe(list) (passing the list function itself)
• ✅ Correct: _asarray_tuplesafe([1, 2, 3]) (passing an actual list)
• ❌ Wrong: _asarray_tuplesafe(df.get_values) (passing a method object without invoking it)
• ✅ Correct: _asarray_tuplesafe(df.get_values()) (passing the result of the method)

Double-check that all arguments passed to _asarray_tuplesafe are iterable sequences, not uninvoked functions/methods.

2. Add defensive checks to the function #

If you want to make the function more robust (to catch these issues early with clearer feedback), add a check for function/method types before trying to convert to a list:

import types
from pandas.core.index import Index

def _asarray_tuplesafe(values, dtype=None):
    # Catch function/method objects before they cause an error
    if isinstance(values, (
        types.BuiltinFunctionType, 
        types.BuiltinMethodType, 
        types.FunctionType, 
        types.MethodType
    )):
        raise ValueError(
            "Expected an iterable sequence (like list/tuple/Index), got a function/method. "
            "Did you forget to call the function/method with parentheses?"
        )
    
    if not (isinstance(values, (list, tuple)) or hasattr(values, '__array__')):
        values = list(values)
    elif isinstance(values, Index):
        return values.values

This will throw a much more descriptive error that tells you exactly what went wrong, instead of the generic "not iterable" message.

内容的提问来源于stack exchange，提问作者Adarsh M Shetty B