user-machine# cd <git_root>
user-machine# pip install -r requirements.txt
user-machine# source env.sh

Run Installation instruction under python virtualenv. Once you have virtualenv installed:

user-machine# virtualenv mypython
user-machine# source mypython/bin/activate
user-machine# pip install -r requirements.txt

user-machine# python generate.py --help
Usage: generate.py [options]

Options:
  --version           show program's version number and exit
  -h, --help          show this help message and exit
  --profile=PROFILE   Take options from a profile file, any CLI targets
                      ignored. Profile options override CLI currently
  -p, --python        Generate Python SDK
  -v, --verbose       Verbose mode
  --no-doc            Skip generation of documentation
  --output-directory  The output-directory . If not specified the output can be found under YDKGEN_HOME/gen-api/python

1. Construct a profile file, such as profiles/xr532-native-oc-bgp.json

2. Generate the SDK using a command of the form:

python generate.py -p --profile profiles/xr532-native-oc-bgp.json

The generated SDK will in <git_root>/ydk/gen-api/python.

A sample profile file is described below.

As should be fairly obvious, the file is in a JSON format. The initial section of metadata is mostly ignored for now. It will be used later.

{
    "version": "0.1.0",
    "Author": "Cisco",
    "Copyright": "Cisco",
    "Description": "Cisco IOS-XR Native Models From Git",

The "models" section of the file describes where to source models from. There are 3 sources:

• Directories
• Specific files
• Git, within which specific relative directories and files may be referenced

The sample below shows the use of git sources only.

    "models": {
        "git": [

We have a list of git sources. Each source must specify a URL. This URL should be one that allows the repository to be cloned without requiring user intervention, so please use a public URL such as the example below. There are three further options that can be specified:

• commitid - Optional specification of a commit in string form. The files identified will be copied from the context of this commit.
• dir - List of relative directory paths within git repository. All .yang files in this directory and any sub-directories will be pulled into the generated SDK.
• file- List of relative file paths within the git repository.

Only directory examples are shown below.

            {
                "url": "https://github.com/YangModels/yang.git",
                "dir": [
                    "vendor/cisco/xr/532"
                ]
            },
            {
                "url": "https://github.com/YangModels/yang.git",
                "commitid": "f6b4e2d59d4eedf31ae8b2fa3119468e4c38259c",
                "dir": [
                    "experimental/openconfig/bgp",
                    "experimental/openconfig/policy"
                ]
            }
        ]
    },

1. Place a copy of the Yang data models <git_root>/ydk/yang

2. Generate Python SDK:

user-machine# python generate.py -p --no-doc

The generated SDK will in <git_root>/ydk/gen-api/python.

The same SDK may be generated using the profile profiles/models-in-repo.json, which also turns documentation generation off:

user-machine# python generate.py --profile profiles/models-in-repo.json

YANG Development Kit Generator:

• Tools that auto generate different programming language binding API's (Python, Ruby, GPB, Thrift, Objective C), Developers can use these objects/APIs, to write application
• Runtime libraries which provided "services" and transport code for App to talk to network devices (runtime for: Python, Ruby, gRPCServer). These runtime libraries also have protocol plugin, currently netconf plug has been added for testing.
• The runtime libraries have three parts:
  • Entity: X object definitions for YANG model. X here is programming language (Python, Ruby, Obj-C, GPBIDL, ThriftIDL etc)
  • Services:
    • CRUDservice: Consume device object and Entity that does "encoding" and "transport" operation specific to "session".

  • ServiceProvider:

For Python entities and netconf session, CRUD service invoked on python class will:

• Encode python data objects to netconf XML payload
• Perform transport operation with device, collect the netconf response,
• Decode netconf response in python class, return result to python app.

Note: The Python API currently supports just the CRUDService. This is internally written over encode/decode api.

README          - install and usage notes
env.sh          - bash environment setup file
gen-api         - source dir or autogenerated SDK 
					- python (Python SDK)

generate.py     - bootstrap script to generate SDK for yang data models
yang            - yang models used by generate.py 
requirements.txt- python dependencies used during installation (refer README)
sdk             - sdk stubs
test            - test code, engg playground 

Make sure that PYTHONPATH is set properly

user-machine# cd <git_root>
user-machine# export PYTHONPATH=.:$PYTHONPATH

To run the generator test case, do the following.

user-machine# cd <git_root>
user-machine# source env.sh
user-machine# python test/pygen_tests.py