Python自省 - 如何从函数内检查当前模块/调用行答案

【问题标题】：Python introspection - how to check current module / line of call from within functionPython自省 - 如何从函数内检查当前模块/调用行
【发布时间】：2011-03-16 14:13:05
【问题描述】：

我有一个函数：

# utils.py
def hello(name='World'):
    # Detect where I'm being called from.
    print('Hi, %s. You called this from %s at line # %d.' % (name, mod, lineno))
    # ``mod`` and ``lineno`` on previous line would have been set in real use.

我导入该函数并在其他地方运行它

# other.py (this comment at line # 138)
from utils import hello
hello('Johnny')  # From inside ``hello`` I want to be able to detect that this
# was called from other.py at line # 140

【问题讨论】：

标签： python introspection

【解决方案1】：

访问inspect.currentframe()的封闭框架：

import inspect

def hello(name='World'):
    f = inspect.currentframe().f_back
    mod = f.f_code.co_filename
    lineno = f.f_lineno
    print('Hi, %s. You called this from %s at line # %d.' %
          (name, mod, lineno))

【讨论】：

【解决方案2】：

traceback 模块让您可以提取堆栈，这样您就可以看到您是如何到达当前堆栈帧的。如果你愿意，你可以扩展它来打印调用者的调用者，只要你喜欢：

import traceback

def _trace():
    stack = traceback.extract_stack()[-3:-1]
    path, line, in_func, _instr = stack[0]
    print 'called from %s in func %s at line %s' % (path, in_func, line)

def bar():
    _trace()

def foo():
    bar()
    baz()

def baz():
    bar()

bar()
foo()

输出：

called from hello.py in func <module> at line 20
called from hello.py in func foo at line 14
called from hello.py in func baz at line 18

【讨论】：

【解决方案3】：

使用warnings 模块。

import warnings

def test(where):
    warnings.warn('hi from test', stacklevel=2)

def foo():
    test('inside foo')

test('from main module')
foo()

结果：

/tmp/test.py:9: UserWarning: hi from test
  test('from main module')
/tmp/test.py:7: UserWarning: hi from test
  test('inside foo')

检查行号。使用 warnings 模块非常棒，因为您的模块的用户可以禁用警告，或者将它们变成完全可检查的异常。

【讨论】：