Metadata-Version: 2.1
Name: cs.csvutils
Version: 20220606
Summary: CSV file related facilities
Home-page: https://bitbucket.org/cameron_simpson/css/commits/all
Author: Cameron Simpson
Author-email: Cameron Simpson <cs@cskk.id.au>
License: GNU General Public License v3 or later (GPLv3+)
Project-URL: URL, https://bitbucket.org/cameron_simpson/css/commits/all
Keywords: python2,python3
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 3
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: Operating System :: OS Independent
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Classifier: License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
Description-Content-Type: text/markdown

Utility functions for CSV files.

*Latest release 20220606*:
* Make csv_reader() a generator to cue the @strable decorator.
* Plumb the new optional snake_case parameter.

In python 2 the stdlib CSV reader reads 8 bit byte data and returns str objects;
these need to be decoded into unicode objects.
In python 3 the stdlib CSV reader reads an open text file and returns str
objects (== unicode).
So we provide `csv_reader()` generators to yield rows containing unicode.

## Function `csv_import(fp, class_name=None, column_names=None, computed=None, preprocess=None, mixin=None, snake_case=False, **kw)`

Read CSV data where the first row contains column headers.
Returns a row namedtuple factory and an iterable of instances.

Parameters:
* `fp`: a file object containing CSV data, or the name of such a file
* `class_name`: optional class name for the namedtuple subclass
  used for the row data.
* `column_names`: optional iterable of column headings; if
  provided then the file is not expected to have internal column
  headings
* `computed`: optional keyword parameter providing a mapping
  of str to functions of `self`; these strings are available
  via __getitem__
* `preprocess`: optional keyword parameter providing a callable
  to modify CSV rows before they are converted into the namedtuple.
  It receives a context object and the data row. It may return
  the row (possibly modified), or None to drop the row.
* `mixin`: an optional mixin class for the generated namedtuple subclass
  to provide extra methods or properties

All other keyword parameters are passed to csv_reader(). This
is a very thin shim around `cs.mappings.named_column_tuples`.

Examples:

      >>> rowtype, rows = csv_import(['a, b', '1,2', '3,4'], class_name='Example_AB')
      >>> rowtype     #doctest: +ELLIPSIS
      <function named_row_tuple.<locals>.factory at ...>
      >>> list(rows)
      [Example_AB(a='1', b='2'), Example_AB(a='3', b='4')]

      >>> rowtype, rows = csv_import(['1,2', '3,4'], class_name='Example_DEFG', column_names=['D E', 'F G '])
      >>> list(rows)
      [Example_DEFG(d_e='1', f_g='2'), Example_DEFG(d_e='3', f_g='4')]

## Function `csv_reader(arg, *a, **kw)`

Read the file `fp` using csv.reader.
`fp` may also be a filename.
Yield the rows.

Warning: _ignores_ the `encoding` and `errors` parameters
because `fp` should already be decoded.

## Function `csv_writerow(csvw, row, encoding='utf-8')`

Write the supplied row as strings encoded with the supplied `encoding`,
default 'utf-8'.

## Function `xl_import(workbook, sheet_name=None, skip_rows=0, **kw)`

Read the named `sheet_name` from the Excel XLSX file named
`filename` as for `csv_import`.
Returns a row namedtuple factory and an iterable of instances.

Parameters:
* `workbook`: Excel work book from which to load the sheet; if
  this is a str then the work book is obtained from
  openpyxl.load_workbook()
* `sheet_name`: optional name of the work book sheet
  whose data should be imported;
  the default (`None`) selects the active worksheet

Other keyword parameters are as for cs.mappings.named_column_tuples.

NOTE: this function requires the `openpyxl` module to be available.

# Release Log



*Release 20220606*:
* Make csv_reader() a generator to cue the @strable decorator.
* Plumb the new optional snake_case parameter.

*Release 20201228*:
Python 3 csv_reader new a generator.

*Release 20191118*:
xl_import: make sheet_name parameter optional with useful default

*Release 20190103*:
Documentation updates.

*Release 20180720*:
csv_import and xl_import function to load spreadsheet exports via cs.mappings.named_column_tuples.

*Release 20170608*:
Recode using new simpler cs.sharedfile.SharedAppendLines.

*Release 20160828*:
* Update metadata with "install_requires" instead of "requires".
* Python 2 and 3 portability fixes.
* Assorted minor improvements.

*Release 20150116*:
Initial PyPI release.
