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Description:

cs.csvutils 20220606

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.