Reading and writing data tables with types and uncertainties (pwkit.tabfile)

pwkit.tabfile - I/O with typed tables of uncertain measurements.

Functions:

read - Read a typed table file. vizread - Read a headerless table file, with columns specified separately write - Write a typed table file.

The table format is line-oriented text. Hashes denote comments. Initial lines of the form “colname = value” set a column name that gets the same value for every item in the table. The header line is prefixed with an @ sign. Subsequent lines are data rows.

pwkit.tabfile.read(path, tabwidth=8, **kwargs)

Read a typed tabular text file into a stream of Holders.

Arguments:

path

The path of the file to read.

tabwidth=8

The tab width to assume. Please don’t monkey with it.

mode=’rt’

The file open mode (passed to io.open()).

noexistok=False

If True and the file is missing, treat it as empty.

**kwargs

Passed to io.open ().

Returns a generator for a stream of pwkit.Holder`s, each of which will contain ints, strings, or some kind of measurement (cf `pwkit.msmt).

pwkit.tabfile.vizread(descpath, descsection, tabpath, tabwidth=8, **kwargs)

Read a headerless tabular text file into a stream of Holders.

Arguments:

descpath

The path of the table description ini file.

descsection

The section in the description file to use.

tabpath

The path to the actual table data.

tabwidth=8

The tab width to assume. Please don’t monkey with it.

mode=’rt’

The table file open mode (passed to io.open()).

noexistok=False

If True and the file is missing, treat it as empty.

**kwargs

Passed to io.open ().

Returns a generator of a stream of pwkit.Holder`s, each of which will contain ints, strings, or some kind of measurement (cf `pwkit.msmt). In this version, the table file does not contain a header, as seen in Vizier data files. The corresponding section in the description ini file has keys of the form “colname = <start> <end> [type]”, where <start> and <end> are the 1-based character numbers defining the column, and [type] is an optional specified of the measurement type of the column (one of the usual b, i, f, u, Lu, Pu).

pwkit.tabfile.write(stream, items, fieldnames, tabwidth=8)

Write a typed tabular text file to the specified stream.

Arguments:

stream

The destination stream.

items

An iterable of items to write. Two passes have to be made over the items (to discover the needed column widths), so this will be saved into a list.

fieldnames

Either a list of field name strings, or a single string. If the latter, it will be split into a list with .split().

tabwidth=8

The tab width to use. Please don’t monkey with it.

Returns nothing.