Commit f031a6f3 authored by R David Murray's avatar R David Murray

#20628: wrap lines to < 80.

parent df714b9f
...@@ -142,40 +142,43 @@ The :mod:`csv` module defines the following functions: ...@@ -142,40 +142,43 @@ The :mod:`csv` module defines the following functions:
The :mod:`csv` module defines the following classes: The :mod:`csv` module defines the following classes:
.. class:: DictReader(csvfile, fieldnames=None, restkey=None, restval=None, dialect='excel', *args, **kwds) .. class:: DictReader(csvfile, fieldnames=None, restkey=None, restval=None, \
dialect='excel', *args, **kwds)
Create an object which operates like a regular reader but maps the information
read into a dict whose keys are given by the optional *fieldnames* parameter. Create an object which operates like a regular reader but maps the
The *fieldnames* parameter is a :mod:`sequence <collections.abc>` whose elements information read into a dict whose keys are given by the optional
are associated with the fields of the input data in order. These elements *fieldnames* parameter. The *fieldnames* parameter is a :mod:`sequence
become the keys of the resulting dictionary. <collections.abc>` whose elements are associated with the fields of the
If the *fieldnames* parameter is omitted, the values in the first row of the input data in order. These elements become the keys of the resulting
*csvfile* will be used as the fieldnames. If the row read has more fields dictionary. If the *fieldnames* parameter is omitted, the values in the
than the fieldnames sequence, the remaining data is added as a sequence first row of the *csvfile* will be used as the fieldnames. If the row read
keyed by the value of *restkey*. If the row read has fewer fields than the has more fields than the fieldnames sequence, the remaining data is added as
fieldnames sequence, the remaining keys take the value of the optional a sequence keyed by the value of *restkey*. If the row read has fewer
*restval* parameter. Any other optional or keyword arguments are passed to fields than the fieldnames sequence, the remaining keys take the value of
the underlying :class:`reader` instance. the optional *restval* parameter. Any other optional or keyword arguments
are passed to the underlying :class:`reader` instance.
.. class:: DictWriter(csvfile, fieldnames, restval='', extrasaction='raise', dialect='excel', *args, **kwds)
.. class:: DictWriter(csvfile, fieldnames, restval='', extrasaction='raise', \
Create an object which operates like a regular writer but maps dictionaries onto dialect='excel', *args, **kwds)
output rows. The *fieldnames* parameter is a :mod:`sequence
<collections.abc>` of keys that identify the order in which values in Create an object which operates like a regular writer but maps dictionaries
the dictionary passed to the :meth:`writerow` method are written to the onto output rows. The *fieldnames* parameter is a :mod:`sequence
*csvfile*. The optional *restval* parameter specifies the value to be written <collections.abc>` of keys that identify the order in which values in the
if the dictionary is missing a key in *fieldnames*. If the dictionary passed to dictionary passed to the :meth:`writerow` method are written to the
the :meth:`writerow` method contains a key not found in *fieldnames*, the *csvfile*. The optional *restval* parameter specifies the value to be
optional *extrasaction* parameter indicates what action to take. If it is set written if the dictionary is missing a key in *fieldnames*. If the
to ``'raise'`` a :exc:`ValueError` is raised. If it is set to ``'ignore'``, dictionary passed to the :meth:`writerow` method contains a key not found in
extra values in the dictionary are ignored. Any other optional or keyword *fieldnames*, the optional *extrasaction* parameter indicates what action to
arguments are passed to the underlying :class:`writer` instance. take. If it is set to ``'raise'`` a :exc:`ValueError` is raised. If it is
set to ``'ignore'``, extra values in the dictionary are ignored. Any other
Note that unlike the :class:`DictReader` class, the *fieldnames* parameter of optional or keyword arguments are passed to the underlying :class:`writer`
the :class:`DictWriter` is not optional. Since Python's :class:`dict` objects instance.
are not ordered, there is not enough information available to deduce the order
in which the row should be written to the *csvfile*. Note that unlike the :class:`DictReader` class, the *fieldnames* parameter
of the :class:`DictWriter` is not optional. Since Python's :class:`dict`
objects are not ordered, there is not enough information available to deduce
the order in which the row should be written to the *csvfile*.
.. class:: Dialect .. class:: Dialect
......
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