###
5.2.6.2 Example Objects

class `Example`( | source, want[, exc_msg][, lineno][, indent][, options])

  A single interactive example, consisting of a Python statement and its expected output. The constructor arguments are used to initialize the member variables of the same names. New in version 2.4.

`Example` defines the following member variables. They are initialized by the constructor, and should not be modified directly.

`source`
  A string containing the example's source code. This source code consists of a single Python statement, and always ends with a newline; the constructor adds a newline when necessary.

`want`
  The expected output from running the example's source code (either from stdout, or a traceback in case of exception). `want` ends with a newline unless no output is expected, in which case it's an empty string. The constructor adds a newline when necessary.

`exc_msg`
  The exception message generated by the example, if the example is expected to generate an exception; or `None` if it is not expected to generate an exception. This exception message is compared against the return value of `traceback.format_exception_only()`. `exc_msg` ends with a newline unless it's `None`. The constructor adds a newline if needed.

`lineno`
  The line number within the string containing this example where the example begins. This line number is zero-based with respect to the beginning of the containing string.

`indent`
  The example's indentation in the containing string, i.e., the number of space characters that preceed the example's first prompt.

`options`
  A dictionary mapping from option flags to `True` or `False`, which is used to override default options for this example. Any option flags not contained in this dictionary are left at their default value (as specified by the `DocTestRunner`'s `optionflags`). By default, no options are set.