HeaderParser

class baseband.vlbi_base.header.HeaderParser(*args, **kwargs)

Bases: collections.OrderedDict

Parser & setter for VLBI header keywords.

An ordered dict of header keywords, with values that describe how they are encoded in a given VLBI header. Initialisation is as a normal OrderedDict, with a key, value pairs. The value should be a tuple containing:

word_index : int

Index into the header words for this key.

bit_index : int

Index to the starting bit of the part used for this key.

bit_length : int

Number of bits.

default : int or bool or None

Possible default value to use in initialisation (e.g., a sync pattern).

The class provides dict-like properties parsers, setters, and defaults, which return functions that get a given keyword from header words, set the corresponding part of the header words to a value, or return the default value (if defined).

Note that while in principle, parsers and setters could be calculated on the fly, we precalculate the parsers to speed up header keyword access.

Attributes Summary

defaults	Dict-like allowing access to default header values.
parsers	Dict with functions to get specific header values.
setters	Dict-like returning function to set specific header value.

Methods Summary

clear()
copy()	Make an independent copy.
fromkeys(S[, v])	If not specified, the value defaults to None.
get(k[,d])
has_key(k)
items()
iteritems()	od.iteritems -> an iterator over the (key, value) pairs in od
iterkeys()
itervalues()	od.itervalues -> an iterator over the values in od
keys()
pop(k[,d])	value.
popitem()	Pairs are returned in LIFO order if last is true or FIFO order if false.
setdefault(k[,d])
update(other)	Update the parser with the information from another one.
values()
viewitems()
viewkeys()
viewvalues()

Attributes Documentation

defaults

Dict-like allowing access to default header values.

parsers

Dict with functions to get specific header values.

setters

Dict-like returning function to set specific header value.

Methods Documentation

clear() → None. Remove all items from od.

copy()

Make an independent copy.

classmethod fromkeys(S[, v]) → New ordered dictionary with keys from S.

If not specified, the value defaults to None.

get(k[, d]) → D[k] if k in D, else d. d defaults to None.

has_key(k) → True if D has a key k, else False

items() → list of (key, value) pairs in od

iteritems()

od.iteritems -> an iterator over the (key, value) pairs in od

iterkeys() → an iterator over the keys in od

itervalues()

od.itervalues -> an iterator over the values in od

keys() → list of keys in od

pop(k[, d]) → v, remove specified key and return the corresponding

value. If key is not found, d is returned if given, otherwise KeyError is raised.

popitem() → (k, v), return and remove a (key, value) pair.

Pairs are returned in LIFO order if last is true or FIFO order if false.

setdefault(k[, d]) → od.get(k,d), also set od[k]=d if k not in od

update(other)

Update the parser with the information from another one.

values() → list of values in od

viewitems() → a set-like object providing a view on od's items

viewkeys() → a set-like object providing a view on od's keys

viewvalues() → an object providing a view on od's values