使用pdb调试python脚本时，有没有获取详细对象信息的方法？
Is there any method of getting detailed object information when using pdb to debug python script?
我正在使用 pdb 调试一个简单的 python 脚本：
#!/usr/bin/python
f = open("./hello.scala")
f.close()
调试流程如下：
[root@localhost ~]# python -m pdb test.py
> /root/test.py(3)<module>()
-> f = open("./hello.scala")
(Pdb) n
> /root/test.py(4)<module>()
-> f.close()
(Pdb) p f
<open file './hello.scala', mode 'r' at 0x7f4d69aae8a0>
(Pdb) pp f
<open file './hello.scala', mode 'r' at 0x7f4d69aae8a0>
我想查看File对象的详细信息f，但我只能得到它的地址。使用pdb调试python脚本时，有没有获取详细对象信息的方法？
您可以在 pdb 中使用大多数任意 Python 表达式。
我不知道 "detailed object information" 你在找什么，但一般来说，任何有用的东西都是一个属性。
因为你知道你有什么类型（file），而且它是 Python 附带的内置或标准库类型，你可以 look it up in the docs 看看有什么属性它保证有。例如，file 对象有一个 closed 属性；看到：
(Pdb) p f.closed
True
如果不知道自己想要什么属性，可以使用inspect模块来帮忙。例如：
(Pdb) import inspect
(Pdb) p inspect.getmembers(f, lambda x: not callable(x))
[('__doc__', "file(name[, mode[, buffering]]) -> file object\n\nOpen a file. The mode can be 'r', 'w' or 'a' for reading (default),\nwriting or appending. The file will be created if it doesn't exist\nwhen opened for writing or appending; it will be truncated when\nopened for writing. Add a 'b' to the mode for binary files.\nAdd a '+' to the mode to allow simultaneous reading and writing.\nIf the buffering argument is given, 0 means unbuffered, 1 means line\nbuffered, and larger numbers specify the buffer size. The preferred way\nto open a file is with the builtin open() function.\nAdd a 'U' to mode to open the file for input with universal newline\nsupport. Any line ending in the input file will be seen as a '\n'\nin Python. Also, a file so opened gains the attribute 'newlines';\nthe value for this attribute is one of None (no newline read yet),\n'\r', '\n', '\r\n' or a tuple containing all the newline types seen.\n\n'U' cannot be combined with 'w' or '+' mode.\n"), ('closed', True), ('encoding', None), ('errors', None), ('mode', 'r'), ('name', 'temp.xml'), ('newlines', None), ('softspace', 0)]
如果你想要它打印得漂亮，只需使用 pp 命令而不是 p:
(Pdb) pp inspect.getmembers(f, lambda x: not callable(x))
[('__doc__',
"file(name[, mode[, buffering]]) -> file object\n\nOpen a file. The mode can be 'r', 'w' or 'a' for reading (default),\nwriting or appending. The file will be created if it doesn't exist\nwhen opened for writing or appending; it will be truncated when\nopened for writing. Add a 'b' to the mode for binary files.\nAdd a '+' to the mode to allow simultaneous reading and writing.\nIf the buffering argument is given, 0 means unbuffered, 1 means line\nbuffered, and larger numbers specify the buffer size. The preferred way\nto open a file is with the builtin open() function.\nAdd a 'U' to mode to open the file for input with universal newline\nsupport. Any line ending in the input file will be seen as a '\n'\nin Python. Also, a file so opened gains the attribute 'newlines';\nthe value for this attribute is one of None (no newline read yet),\n'\r', '\n', '\r\n' or a tuple containing all the newline types seen.\n\n'U' cannot be combined with 'w' or '+' mode.\n"),
('closed', True),
('encoding', None),
('errors', None),
('mode', 'r'),
('name', 'temp.xml'),
('newlines', None),
('softspace', 0)]
正如文档在顶部附近解释的那样：
The getmembers() function retrieves the members of an object such as a class or module. The sixteen functions whose names begin with “is” are mainly provided as convenient choices for the second argument to getmembers().
但这16个函数你不一定要用，你想传什么就传什么。正如 getmembers 文档所说：
Return all the members of an object in a list of (name, value) pairs sorted by name. If the optional predicate argument is supplied, only members for which the predicate returns a true value are included.
因此，作为示例，我编写了一个自定义函数 lambda x: not callable(x)，它仅适用于不可调用的成员。这意味着我不会得到 close 方法之类的东西，只会得到 closed 属性之类的东西。
如果你不明白lambda，这是一种在表达式中间定义简单函数的方法。就像我写的一样：
def my_function(x):
return not callable(x)
…然后调用inspect.getmembers(f, my_function).
在我们讨论的同时，您可能想看看 IPython，它是默认 Python 交互模式的替代品。除其他外，它还为您提供了 Pdb 中的制表符补全功能（以及正常的交互式会话）：
ipdb> n
--Return--
None
> /Users/abarnert/src/pt.py(2)<module>()
1 1 f = open('temp.txt')
----> 2 f.close()
ipdb> p f
<_io.TextIOWrapper name='temp.xml' mode='r' encoding='UTF-8'>
ipdb> p f.
f.buffer f.fileno f.newlines f.seekable
f.close f.flush f.read f.tell
f.closed f.isatty f.readable f.truncate
f.detach f.line_buffering f.readline f.writable
f.encoding f.mode f.readlines f.write
f.errors f.name f.seek f.writelines
ipdb> p f.
（很抱歉在该示例记录中使用了 Python 3；我的 Python 2.7 正在升级 IPython...）
据我所知，最简单的方法是在 .pdbrc 文件中定义别名。
您可以在其中找到 pi 别名（"print instance" 的缩写），它几乎可以满足您的需求。
那里还有其他有用的别名。
非常有用，强烈推荐。
我正在使用 pdb 调试一个简单的 python 脚本：
#!/usr/bin/python
f = open("./hello.scala")
f.close()
调试流程如下：
[root@localhost ~]# python -m pdb test.py
> /root/test.py(3)<module>()
-> f = open("./hello.scala")
(Pdb) n
> /root/test.py(4)<module>()
-> f.close()
(Pdb) p f
<open file './hello.scala', mode 'r' at 0x7f4d69aae8a0>
(Pdb) pp f
<open file './hello.scala', mode 'r' at 0x7f4d69aae8a0>
我想查看File对象的详细信息f，但我只能得到它的地址。使用pdb调试python脚本时，有没有获取详细对象信息的方法？
您可以在 pdb 中使用大多数任意 Python 表达式。
我不知道 "detailed object information" 你在找什么，但一般来说，任何有用的东西都是一个属性。
因为你知道你有什么类型（file），而且它是 Python 附带的内置或标准库类型，你可以 look it up in the docs 看看有什么属性它保证有。例如，file 对象有一个 closed 属性；看到：
(Pdb) p f.closed
True
如果不知道自己想要什么属性，可以使用inspect模块来帮忙。例如：
(Pdb) import inspect
(Pdb) p inspect.getmembers(f, lambda x: not callable(x))
[('__doc__', "file(name[, mode[, buffering]]) -> file object\n\nOpen a file. The mode can be 'r', 'w' or 'a' for reading (default),\nwriting or appending. The file will be created if it doesn't exist\nwhen opened for writing or appending; it will be truncated when\nopened for writing. Add a 'b' to the mode for binary files.\nAdd a '+' to the mode to allow simultaneous reading and writing.\nIf the buffering argument is given, 0 means unbuffered, 1 means line\nbuffered, and larger numbers specify the buffer size. The preferred way\nto open a file is with the builtin open() function.\nAdd a 'U' to mode to open the file for input with universal newline\nsupport. Any line ending in the input file will be seen as a '\n'\nin Python. Also, a file so opened gains the attribute 'newlines';\nthe value for this attribute is one of None (no newline read yet),\n'\r', '\n', '\r\n' or a tuple containing all the newline types seen.\n\n'U' cannot be combined with 'w' or '+' mode.\n"), ('closed', True), ('encoding', None), ('errors', None), ('mode', 'r'), ('name', 'temp.xml'), ('newlines', None), ('softspace', 0)]
如果你想要它打印得漂亮，只需使用 pp 命令而不是 p:
(Pdb) pp inspect.getmembers(f, lambda x: not callable(x))
[('__doc__',
"file(name[, mode[, buffering]]) -> file object\n\nOpen a file. The mode can be 'r', 'w' or 'a' for reading (default),\nwriting or appending. The file will be created if it doesn't exist\nwhen opened for writing or appending; it will be truncated when\nopened for writing. Add a 'b' to the mode for binary files.\nAdd a '+' to the mode to allow simultaneous reading and writing.\nIf the buffering argument is given, 0 means unbuffered, 1 means line\nbuffered, and larger numbers specify the buffer size. The preferred way\nto open a file is with the builtin open() function.\nAdd a 'U' to mode to open the file for input with universal newline\nsupport. Any line ending in the input file will be seen as a '\n'\nin Python. Also, a file so opened gains the attribute 'newlines';\nthe value for this attribute is one of None (no newline read yet),\n'\r', '\n', '\r\n' or a tuple containing all the newline types seen.\n\n'U' cannot be combined with 'w' or '+' mode.\n"),
('closed', True),
('encoding', None),
('errors', None),
('mode', 'r'),
('name', 'temp.xml'),
('newlines', None),
('softspace', 0)]
正如文档在顶部附近解释的那样：
The
getmembers()function retrieves the members of an object such as a class or module. The sixteen functions whose names begin with “is” are mainly provided as convenient choices for the second argument togetmembers().
但这16个函数你不一定要用，你想传什么就传什么。正如 getmembers 文档所说：
Return all the members of an object in a list of (name, value) pairs sorted by name. If the optional predicate argument is supplied, only members for which the predicate returns a true value are included.
因此，作为示例，我编写了一个自定义函数 lambda x: not callable(x)，它仅适用于不可调用的成员。这意味着我不会得到 close 方法之类的东西，只会得到 closed 属性之类的东西。
如果你不明白lambda，这是一种在表达式中间定义简单函数的方法。就像我写的一样：
def my_function(x):
return not callable(x)
…然后调用inspect.getmembers(f, my_function).
在我们讨论的同时，您可能想看看 IPython，它是默认 Python 交互模式的替代品。除其他外，它还为您提供了 Pdb 中的制表符补全功能（以及正常的交互式会话）：
ipdb> n
--Return--
None
> /Users/abarnert/src/pt.py(2)<module>()
1 1 f = open('temp.txt')
----> 2 f.close()
ipdb> p f
<_io.TextIOWrapper name='temp.xml' mode='r' encoding='UTF-8'>
ipdb> p f.
f.buffer f.fileno f.newlines f.seekable
f.close f.flush f.read f.tell
f.closed f.isatty f.readable f.truncate
f.detach f.line_buffering f.readline f.writable
f.encoding f.mode f.readlines f.write
f.errors f.name f.seek f.writelines
ipdb> p f.
（很抱歉在该示例记录中使用了 Python 3；我的 Python 2.7 正在升级 IPython...）
据我所知，最简单的方法是在 .pdbrc 文件中定义别名。
您可以在其中找到 pi 别名（"print instance" 的缩写），它几乎可以满足您的需求。
那里还有其他有用的别名。
非常有用，强烈推荐。