_csv

CSV parsing and writing.

This module provides classes that assist in the reading and writing
of Comma Separated Value (CSV) files, and implements the interface
described by PEP 305.  Although many CSV files are simple to parse,
the format is not formally defined by a stable specification and
is subtle enough that parsing lines of a CSV file with something
like line.split(",") is bound to fail.  The module supports three
basic APIs: reading, writing, and registration of dialects.


DIALECT REGISTRATION:

Readers and writers support a dialect argument, which is a convenient
handle on a group of settings.  When the dialect argument is a string,
it identifies one of the dialects previously registered with the module.
If it is a class or instance, the attributes of the argument are used as
the settings for the reader or writer:

    class excel:
        delimiter = ','
        quotechar = '"'
        escapechar = None
        doublequote = True
        skipinitialspace = False
        lineterminator = '\r\n'
        quoting = QUOTE_MINIMAL

SETTINGS:

    * quotechar - specifies a one-character string to use as the
        quoting character.  It defaults to '"'.
    * delimiter - specifies a one-character string to use as the
        field separator.  It defaults to ','.
    * skipinitialspace - specifies how to interpret spaces which
        immediately follow a delimiter.  It defaults to False, which
        means that spaces immediately following a delimiter is part
        of the following field.
    * lineterminator -  specifies the character sequence which should
        terminate rows.
    * quoting - controls when quotes should be generated by the writer.
        It can take on any of the following module constants:

        csv.QUOTE_MINIMAL means only when required, for example, when a
            field contains either the quotechar or the delimiter
        csv.QUOTE_ALL means that quotes are always placed around fields.
        csv.QUOTE_NONNUMERIC means that quotes are always placed around
            fields which do not parse as integers or floating point
            numbers.
        csv.QUOTE_NONE means that quotes are never placed around fields.
    * escapechar - specifies a one-character string used to escape
        the delimiter when quoting is set to QUOTE_NONE.
    * doublequote - controls the handling of quotes inside fields.  When
        True, two consecutive quotes are interpreted as one during read,
        and when writing, each quote character embedded in the data is
        written as two quotes

Classes

Dialect

CSV dialect

The Dialect type records CSV parsing and generation options.

delimiter = <attribute 'delimiter' of '_csv.Dialect' objects>

doublequote = <member 'doublequote' of '_csv.Dialect' objects>

escapechar = <attribute 'escapechar' of '_csv.Dialect' objects>

lineterminator = <attribute 'lineterminator' of '_csv.Dialect' objects>

quotechar = <attribute 'quotechar' of '_csv.Dialect' objects>

quoting = <attribute 'quoting' of '_csv.Dialect' objects>

skipinitialspace = <member 'skipinitialspace' of '_csv.Dialect' objects>

strict = <member 'strict' of '_csv.Dialect' objects>

Error

with_traceback(...)

  Exception.with_traceback(tb) --
      set self.__traceback__ to tb and return self.

args = <attribute 'args' of 'BaseException' objects>

reader

CSV reader

Reader objects are responsible for reading and parsing tabular data
in CSV format.

dialect = <member 'dialect' of '_csv.reader' objects>

line_num = <member 'line_num' of '_csv.reader' objects>

writer

CSV writer

Writer objects are responsible for generating tabular data
in CSV format from sequence input.

writerow(...)

  writerow(iterable)

  Construct and write a CSV record from an iterable of fields.  Non-string
  elements will be converted to string.

writerows(...)

  writerows(iterable of iterables)

  Construct and write a series of iterables to a csv file.  Non-string
  elements will be converted to string.

dialect = <member 'dialect' of '_csv.writer' objects>

Functions

field_size_limit

field_size_limit(...)

  Sets an upper limit on parsed fields.
      csv.field_size_limit([limit])

  Returns old limit. If limit is not given, no new limit is set and
  the old limit is returned

get_dialect

get_dialect(...)

  Return the dialect instance associated with name.
      dialect = csv.get_dialect(name)

list_dialects

list_dialects(...)

  Return a list of all know dialect names.
      names = csv.list_dialects()

reader

reader(...)

      csv_reader = reader(iterable [, dialect='excel']
                          [optional keyword args])
      for row in csv_reader:
          process(row)

  The "iterable" argument can be any object that returns a line
  of input for each iteration, such as a file object or a list.  The
  optional "dialect" parameter is discussed below.  The function
  also accepts optional keyword arguments which override settings
  provided by the dialect.

  The returned object is an iterator.  Each iteration returns a row
  of the CSV file (which can span multiple input lines).

register_dialect

register_dialect(...)

  Create a mapping from a string name to a dialect class.
      dialect = csv.register_dialect(name[, dialect[, **fmtparams]])

unregister_dialect

unregister_dialect(...)

  Delete the name/dialect mapping associated with a string name.
      csv.unregister_dialect(name)

writer

writer(...)

      csv_writer = csv.writer(fileobj [, dialect='excel']
                              [optional keyword args])
      for row in sequence:
          csv_writer.writerow(row)

      [or]

      csv_writer = csv.writer(fileobj [, dialect='excel']
                              [optional keyword args])
      csv_writer.writerows(rows)

  The "fileobj" argument can be any object that supports the file API.

Other members

QUOTE_ALL = 1

QUOTE_MINIMAL = 0

QUOTE_NONE = 3

QUOTE_NONNUMERIC = 2