Add sample python code for DIDs and Price Oracles (#2932)

* Create create_price_oracle.py

* Create README.md

* Update README.md

* Update create_price_oracle.py

* Create delete_price_oracle.py

* Update delete_price_oracle.py

* Create account_price_oracles.py

* Create did_set.py

* Create did_delete.py

* Create account_did.py

* Create requirements.txt

* Create README.md

* Create requirements.txt

* Update README.md

* Update README.md

* Create README.md

* Create README.md

* Update did_set.py

* Update did_set.py

* Update did_set.py

* Update did_delete.py

* Update README.md

* Update create_price_oracle.py

* Update did_set.py

* Update README.md

* Update README.md

* Update delete_price_oracle.py

* Update README.md

_code-samples/did/README.md

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+# Create, Update, and Delete Decentralized Identifiers (DIDs)
+
+Create, Update, and Delete Decentralized Identifiers (DIDs). A Decentralized Identifier (DID) is a new type of identifier defined by the World Wide Web Consortium (W3C) that enables verifiable, digital identities.

_code-samples/did/py/README.md

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+# How to DID
+
+Modify and run the did_set.py file to create or update a DID object for an XRPL account.
+
+After you run the did_set.py file it returns a seed which you will input upon request from the did_delete.py file to delete the account's DID

_code-samples/did/py/account_did.py

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+from xrpl.models import LedgerEntry
+from xrpl.clients import JsonRpcClient
+
+
+# connect to the xrpl via a client
+print("Connecting to client")
+client = JsonRpcClient("https://s.altnet.rippletest.net:51234")
+print("connected!!!")
+
+
+# address of an account that has an existing DID
+account_did_creator = "rQB1cBMMyFXshFQd6cj3eg7vSJZtYb6d8e"
+
+# build the request for the account's DID
+req = LedgerEntry(ledger_index="validated", did=account_did_creator)
+
+# submit request and awaiting result
+print("submitting request")
+response = client.request(req)
+result = response.result
+
+
+# parse result
+if "index" in result and "Account" in result["node"]:
+    print(f'DID index: {result["node"]["index"]}')
+    print(f'DID Document: {result["node"]["DIDDocument"]}')
+    print(f'Data: {result["node"]["Data"]}')
+    print(f'URI: {result["node"]["URI"]}')
+else:
+    print("No DID found for this account")

_code-samples/did/py/did_delete.py

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+# neccasary imports
+from xrpl.models import DIDDelete
+from xrpl.clients import JsonRpcClient
+from xrpl.wallet import Wallet
+from xrpl.transaction import submit_and_wait
+
+
+# connect to the xrpl via a client
+print("Connecting to client")
+client = JsonRpcClient("https://s.altnet.rippletest.net:51234")
+print("connected!!!")
+
+
+# input the seed that was generated from running the did_set.py
+seed = input("now, enter the seed of the account that has a DID object to delete: ")
+
+# restore an account that has an existing DID
+account_did_creator = Wallet.from_seed(seed=seed)
+
+# define the account DIDDelete transaction
+did_delete_txn = DIDDelete(account=account_did_creator.address)
+
+# sign, submit the did delete transaction and wait for result
+print("signed and submitting did delete transaction. awaiting response...")
+did_delete_response = submit_and_wait(
+    transaction=did_delete_txn,
+    wallet=account_did_creator,
+    client=client,
+)
+
+# Parse response for result
+did_delete_result = did_delete_response.result
+
+# Print result and transaction hash
+print(did_delete_result["meta"]["TransactionResult"])
+print(did_delete_result["hash"])

_code-samples/did/py/did_set.py

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+# This allows you to create or update a DID
+from xrpl.models import DIDSet
+from xrpl.clients import JsonRpcClient
+from xrpl.wallet import generate_faucet_wallet
+from xrpl.transaction import submit_and_wait
+from xrpl.utils import str_to_hex
+
+
+# connect to the xrpl via a client
+print("Connecting to client")
+client = JsonRpcClient("https://s.altnet.rippletest.net:51234")
+print("connected!!!")
+
+
+# define/generate a wallet / account
+account_did_creator = generate_faucet_wallet(client)
+
+print("⭐successfully generated wallet")
+print("here's your seed. You'll need it to modify and delete the DID set by this account/wallet")
+# it is not good practise to expose your seed.
+print(f"seed: {account_did_creator.seed}")
+
+
+# define the document associated with the DID
+document = "did:example:123#public-key-0"
+
+# define the data associated with the DID
+# The public attestations of identity credentials associated with the DID.
+data = "did:example:123#key-1"
+
+# define the uri associated with the DID
+# The Universal Resource Identifier associated with the DID.
+uri = "https://example.did.com/123"
+
+
+# build DID SET transaction
+# str_to_hex() converts the inputted string to blockchain understandable hexadecimal
+did_set_txn = DIDSet(
+    account=account_did_creator.address,
+    did_document=str_to_hex(document),
+    data=str_to_hex(data),
+    uri=str_to_hex(uri),
+)
+
+
+# sign, submit the transaction and wait for the response
+print("siging and submitting the transaction, awaiting a response")
+did_set_txn_response = submit_and_wait(
+    transaction=did_set_txn, client=client, wallet=account_did_creator
+)
+
+# Parse response for result
+did_set_txn_result = did_set_txn_response.result
+
+# Print result and transaction hash
+print(did_set_txn_result["meta"]["TransactionResult"])
+print(did_set_txn_result["hash"])

_code-samples/did/py/requirements.txt

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+xrpl-py==4.0.0