python - 如何使用 python 帮助来归档函数

Question

如果我想查看str.replace()函数:help(str.replace)结果是:

Help on method_descriptor:

replace(...)
    S.replace(old, new[, count]) -> str

    Return a copy of S with all occurrences of substring
    old replaced by new.  If the optional argument count is
    given, only the first count occurrences are replaced.
(END)

但是如何使用帮助file.read或readlines？例如， help(file.read) 和 help(read) 都是错误:

>>> help(file)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'file' is not defined
>>> help(file.read)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'file' is not defined
>>> help(read)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'read' is not defined

如何使用帮助查看文件功能？

Answer 1

file 类型已从 Python 3 中删除。查看 io module相反:

>>> import io
>>> help(io.TextIOBase.read)

Help on method_descriptor:

read(...)
    Read at most n characters from stream.

    Read from underlying buffer until we have n characters or we hit EOF.
    If n is negative or omitted, read until EOF.