List Replace
============

You are required to deliver the following function in the module :mod:`list_replace` (file :file:`list_replace.py`):

    .. py:function:: list_replace(Ls, c1, c2)

such that

    **given**

        - *Ls* a :class:`list` of :class:`str`
        - *c1*, *c2*, both one-character :class:`str`

    **modifies** *Ls* by having all ocurrences of *c1* replaced by *c2* in all strings in *Ls* up to the first string where *c1* does not occur.

    and **returns** an :class:`int` with the sum of all replacements done.

For example:

    .. literalinclude:: list_replace.test
        :language: python3
        :start-after: --ini
        :end-before: --fi

Doctests are available in the :download:`list_replace.test` file.