MetadataProxy

class Stoner.folders.metadata.MetadataProxy(folder)

Bases: MutableMapping

Provide methods to interact with a whole collection of metadataObjects’ metadata.

Attributes Summary

all	List all the metadata dictionaries in the Folder.
all_by_keys	Return the set of metadata keys common to all objects int he Folder.
common_keys	Return the set of metadata keys common to all objects int he Folder.
common_metadata	Return a dictionary of the common_keys that have common values.

Methods Summary

all_items()	Return the result of indexing the metadata with all_keys().
all_keys()	Return the union of all the metadata keyus for all objects int he Folder.
all_values()	Return the result of indexing the metadata with all_keys().
apply(key, func)	Evaluate a function for each item in the folder and store the return value in a metadata key.
clear()
get(k[,d])
items()
keys()
pop(k[,d])	If key is not found, d is returned if given, otherwise KeyError is raised.
popitem()	as a 2-tuple; but raise KeyError if D is empty.
setdefault(k[,d])
slice(*args, **kwargs)	Return a list of the metadata dictionaries for each item/file in the top level group.
update([E, ]**F)	If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k, v in F.items(): D[k] = v
values()

Attributes Documentation

all

List all the metadata dictionaries in the Folder.

all_by_keys

Return the set of metadata keys common to all objects int he Folder.

common_keys

Return the set of metadata keys common to all objects int he Folder.

common_metadata

Return a dictionary of the common_keys that have common values.

Methods Documentation

all_items()

Return the result of indexing the metadata with all_keys().

Yields:

key,self[key]

all_keys()

Return the union of all the metadata keyus for all objects int he Folder.

all_values()

Return the result of indexing the metadata with all_keys().

Yields:

self[key]

apply(key, func)

Evaluate a function for each item in the folder and store the return value in a metadata key.

Parameters:

• key (str) – The name of the key to store the result in.

• func (callable) – The function to be evaluated.

Returns:

(self) a copy of the combined metadata object to allow routines to be strung together.

Notes

The function should have a protoptye of the form:

def func(i,metadataObject):

where i is a counter that runs from 0 to the length of the current Folder and metadataObject will be each object in the Folder in turn.

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

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

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

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

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), remove and return some (key, value) pair

as a 2-tuple; but raise KeyError if D is empty.

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

slice(*args, **kwargs)

Return a list of the metadata dictionaries for each item/file in the top level group.

Keyword Arguments:

• *args (string, lmfit.Model class or instance or iterable of string, lmfit Models) – if given then only return the item(s) requested from the metadata

• values_only (bool) – if given and output not set only return tuples of the dictionary values. Mostly useful when given a single key string

• output (str or type) –

  Controls the output format from slice_metadata. Possible values are

  • ”dict” or dict - return a list of dictionary subsets of the metadata from each image

  • ”list” or list - return a list of values of each item pf the metadata

  • ”array” or np.array - return a single array - like list above, but returns as a numpy array. This can create a 2D array from multiple keys

  • ”data” or Stoner.Data - returns the metadata in a Stoner.Data object where the column headers are the metadata keys.

  • ”frame” - returns the metadata as a Pandas DataFrame object

  • ”smart” - switch between dict and list depending whether there is one or more keys.

• mask_missing (bool) – If true, then metadata entries missing in members of the folder are returned as masked values (or None), If False, then an exception is raised if any entries are missing.

Returns:

ret(list of dict, tuple of values or Stoner.Data) – depending on values_only or (output* returns the sliced dictionaries or tuples/ values of the items

update([E, ]**F) → None.  Update D from mapping/iterable E and F.

If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k, v in F.items(): D[k] = v

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