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Diffstat (limited to 'Doc/library/csv.rst')
| -rw-r--r-- | Doc/library/csv.rst | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst index a20c4be..e82c376 100644 --- a/Doc/library/csv.rst +++ b/Doc/library/csv.rst @@ -145,7 +145,10 @@ The :mod:`csv` module defines the following classes: .. 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. + read into a dict whose keys are given by the optional *fieldnames* parameter. + The *fieldnames* parameter is a :mod:`sequence <collections.abc>` whose elements + are associated with the fields of the input data in order. These elements + become the keys of the resulting dictionary. If the *fieldnames* parameter is omitted, the values in the first row of the *csvfile* will be used as the fieldnames. If the row read has more fields than the fieldnames sequence, the remaining data is added as a sequence @@ -158,7 +161,8 @@ The :mod:`csv` module defines the following classes: .. class:: DictWriter(csvfile, fieldnames, restval='', extrasaction='raise', dialect='excel', *args, **kwds) Create an object which operates like a regular writer but maps dictionaries onto - output rows. The *fieldnames* parameter identifies the order in which values in + output rows. The *fieldnames* parameter is a :mod:`sequence + <collections.abc>` of keys that identify the order in which values in the dictionary passed to the :meth:`writerow` method are written to the *csvfile*. The optional *restval* parameter specifies the value to be written if the dictionary is missing a key in *fieldnames*. If the dictionary passed to |