Input File Format
To maintain uniformity, PypeIt uses a standard format for all of the input files used by the Command-line Scripts. This document describes that format and its main components. The specifics of the various input file types (e.g. PypeIt Reduction File) are described throughout the documents. We also provide a listing of the primary files at the end of this page.
Comments in the Input File Format are indicated by
# and are always ignored.
The main three components of a PypeIt input file are:
The individual file types make use of one or more of these components as needed. Their ordering is not strict, although the code writes to disk in the order above.
We now described each in turn.
Most of the input files require input from the user and/or allow for the user to make modifications to the default parameters of the pipeline. This information is ingested in a series of lines that we refer to as the Parameter Block.
# User-defined execution parameters
spectrograph = shane_kast_blue
edge_thresh = 100
The formatting is dict-like, with each level of the dict set by the key in
 and the eventual key/item pair marked by assignment. Note that the
indentation is not strictly required, but the number of square brackets
indicating the dictionary hierarchy is required. That is, in the example
slitedges is a sub-dictionary within
calibrations as indicated by
the double brackets.
The third component is a data block which itself consists
of two components: a line-by-line set of data paths and
| delimited table of data. The latter usually contains
at a minimum the filenames to be processed by a
A data block is marked by a pair of starting
xxx end lines where
xxx is specific
to the type of input file. Here is an example for a
PypeIt Reduction File:
# Data block
filename | date | frametype | target | exptime | disp name | decker
b1.fits.gz | 2015-05-20T01:35:58.10 | arc | Arcs | 30 | 600/ 4310 | 0.5 arcsec
b27.fits.gz | 2015-05-20T04:57:33.56 | science | J1217p3905 | 1200 | 600/ 4310 | 2.0 arcsec
We now describe the two parts of the data block
The lines following the
xxx read describe the path(s)
to the files. Each line should start with
then be followed by a relative or absolute path. We
strongly recommend using the absolute path.
paths portion is a
| delimited table that
provides data. It usually contains, at minimum, a single column
specifying the files to be processed by the script.
That would look like:
# Data block
Here, the column name (
filename) is trivial and a bit awkward,
but it is also required.
Many files use a multi-column table with | delimiters, e.g.:
# Data block
filename | obj_id
spec1d_b27-J1217p3905_KASTb_2015May20T045733.560.fits | SPAT0176-SLIT0000-DET01
spec1d_b28-J1217p3905_KASTb_2015May20T051801.470.fits | SPAT0175-SLIT0000-DET01
Docs on Pypeit Input Files
Here are links to the detailed docs on the main set of PypeIt input files: