ncdiff.Model class

class ncdiff.Model(tree)

Bases: object

Abstraction of a YANG module. It supports str() which returns a string similar to the output of ‘pyang -f tree’.

name

Model name.

Type:str

prefix

Prefix of the model.

Type:str

prefixes

All prefixes used in the model. Dictionary keys are prefixes, and values are URLs.

Type:dict

url

URL of the model.

Type:str

urls

All URLs used in the model. Dictionary keys are URLs, and values are prefixes.

Type:dict

tree

The model tree as an Element object.

Type:Element

roots

All root nodes of the model. Each node is an Element object.

Type:list

width

This is used to facilitate pretty print of a model. Dictionary keys are nodes in the model tree, and values are indents.

Type:dict

__init__ instantiates a Model instance.

emit_tree(tree)

High-level api: Emit a string presentation of the model.

Parameters:tree (Element) – The model. Returns:A string presentation of the model that is very similar to the output of ‘pyang -f tree’ Return type:str

emit_children(tree, type='other')

High-level api: Emit a string presentation of a part of the model.

Parameters:

• tree (Element) – The model.
• type (str) – Type of model content required. Its value can be ‘other’, ‘rpc’, or ‘notification’.

Returns:

A string presentation of the model that is very similar to the output of ‘pyang -f tree’

Return type:

str

get_width(element)

High-level api: Calculate how much indent is needed for a node.

Parameters:element (Element) – A node in model tree. Returns:Start position from the left margin. Return type:int

static get_depth_str(element, type='other')

High-level api: Produce a string that represents tree hierarchy.

Parameters:

• element (Element) – A node in model tree.
• type (str) – Type of model content required. Its value can be ‘other’, ‘rpc’, or ‘notification’.

Returns:

A string that represents tree hierarchy.

Return type:

str

static get_flags_str(element)

High-level api: Produce a string that represents the type of a node.

Parameters:element (Element) – A node in model tree. Returns:A string that represents the type of a node. Return type:str

get_name_str(element)

High-level api: Produce a string that represents the name of a node.

Parameters:element (Element) – A node in model tree. Returns:A string that represents the name of a node. Return type:str

get_datatype_str(element, length)

High-level api: Produce a string that indicates the data type of a node.

Parameters:

• element (Element) – A node in model tree.
• length (int) – String length that has been consumed.

Returns:

A string that indicates the data type of a node.

Return type:

str

prefix_to_url(id)

High-level api: Convert an identifier from prefix:tagname notation to {namespace}tagname notation. If the identifier does not have a prefix, it is assumed that the whole identifier is a tag name.

Parameters:id (str) – Identifier in prefix:tagname notation. Returns:Identifier in {namespace}tagname notation. Return type:str

url_to_prefix(id)

High-level api: Convert an identifier from {namespace}tagname notation to prefix:tagname notation. If the identifier does not have a namespace, it is assumed that the whole identifier is a tag name.

Parameters:id (str) – Identifier in {namespace}tagname notation. Returns:Identifier in prefix:tagname notation. Return type:str

remove_model_prefix(id)

High-level api: If prefix is the model prefix, return tagname without prefix. If prefix is not the model prefix, simply return the identifier without modification.

Parameters:id (str) – Identifier in prefix:tagname notation. Returns:Identifier in prefix:tagname notation if prefix is not the model prefix. Or identifier in tagname notation if prefix is the model prefix. Return type:str

convert_tree()

High-level api: Convert cxml tree to an internal schema tree.

Parameters:None – Returns:This is the tree after convertion. Return type:Element