Add py con escrow & video

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ddawson
2023-10-16 17:45:52 -07:00
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@@ -60,7 +60,11 @@ To get test accounts:
### Create Conditional Escrow:
When you create a conditional escrow, you need to specify the `Condition` value you generated above. You must also set a cancel date and time, after which the escrow is no longer available.
<div align="center">
<iframe width="560" height="315" src="https://www.youtube.com/embed/jUQ2nM5JXjc?si=-ajV2EFw8xv4djgG" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
</div>
When you create a conditional escrow, you need to specify the amount you want to reserve and the `Condition` value you generated above. You must also set a cancel date and time, after which the escrow is no longer available.
To create a conditional escrow:

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---
html: py-create-conditional-escrows.html
parent: send-payments-using-python.html
blurb: Create, finish, or cancel condition-based escrow transactions.
labels:
- Accounts
- Quickstart
- Transaction Sending
- XRP
---
# Create Conditional Escrows Using Python
This example shows how to:
1. Create escrow payments that become available when any account enters a fulfillment code.
2. Complete a conditional escrow transaction.
3. Cancel a conditional escrow transaction.
[![Conditional Escrow Tester Form](img/quickstart-py-conditional-escrow-1.png)](img/quickstart-py-conditional-escrow-1.png)
## Prerequisites
Download and expand the [Quickstart Samples](https://github.com/XRPLF/xrpl-dev-portal/tree/master/content/_code-samples/quickstart/py/){.github-code-download} archive.
## Usage
### Create Escrow
You create a condition-based escrow using a fulfillment code associated with a condition code. Create the condition/fulfillment pair using the `five-bells-condition` application.
Install `five-bells-condition`:
1. In a terminal window, navigate to your local `Quickstart` directory (for convenience).
2. Enter the command `npm install five-bells-condition`.
To create a condition/fulfillment pair:
1. In a terminal window, navigate to your `Quickstart` directory.
2. Enter the command `node getConditionAndFulfillment.js`.
3. Copy and save the generated Condition and Fulfillment pair.
[![Condition and Fulfillment](img/conditional-escrow2.png)](img/conditional-escrow2.png)
To get test accounts:
1. Open and run `lesson9-conditional-escrow.py`.
2. Get test accounts.
1. If you have existing account seeds
1. Paste Standby account seed in the **Standby Seed** field.
2. Click **Get Standby Account**.
3. Click **Get Standby Account Info**.
4. Paste Operational account seed in the **Operational Seed** field.
5. Click **Get Operational Account**.
6. Click **Get Op Account Info**.
2. If you do not have account seeds:
1. Click **Get Standby Account**.
2. Click **Get Standby Account Info**.
3. Click **Get Operational Account**.
4. Click **Get Op Account Info**.
[![Escrow Tester with Account Information](img/quickstart-py-conditional-escrow-2.png)](img/quickstart-py-conditional-escrow-2.png)
### Create Conditional Escrow:
<div align="center">
<iframe width="560" height="315" src="https://www.youtube.com/embed/nWaMAr84qR0?si=LkF-vwQ3QJ4XNhJA" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
</div>
When you create a conditional escrow, you need to specify the `Condition` value you generated above. You must also set a cancel date and time, after which the escrow is no longer available.
To create a conditional escrow:
1. Enter an **Amount** to transfer.
2. Copy the **Operational Account** value.
3. Paste it in the **Destination Account** field.
4. Enter the **Escrow Condition** value.
5. Enter the **Escrow Cancel (seconds)** value.
6. Click **Create Escrow**.
7. Copy and save the _Sequence Number_ of the escrow called out in the **Standby Result** field.
The escrow is created on the XRP Ledger instance, reserving your requested XRP amount plus the transaction cost.
When you create an escrow, capture and save the _Sequence Number_ so that you can use it to finish the escrow transaction.
[![Created Escrow Transaction](img/quickstart-py-conditional-escrow-3.png)](img/quickstart-py-conditional-escrow-3.png)
## Finish Conditional Escrow
Any account can finish the conditional escrow any time before the _Escrow Cancel_ time. Following on the example above, you can use the _Sequence Number_ to finish the transaction once the Escrow Cancel time has passed.
To finish a conditional escrow:
1. Paste the sequence number in the Operational account **Sequence Number** field.
2. Enter the **Escrow Condition** value.
3. Enter the **Escrow Fulfillment** code for the `Condition`.
4. Click **Finish Conditional Escrow**.
The transaction completes and balances are updated for both the Standby and Operational accounts.
[![Finished Escrow Transaction](img/quickstart-py-conditional-escrow-4.png)](img/quickstart-py-conditional-escrow-4.png)
## Get Escrows
Click **Get Escrows** for either the Standby account or the Operational account to see their current list of escrows.
## Cancel Escrow
When the Escrow Cancel time passes, the escrow is no longer available to the recipient. The initiator of the escrow can reclaim the XRP, less the transaction fees. Any account can cancel an escrow once the cancel time has elapsed. Accounts that try to cancel the transaction prior to the **Escrow Cancel** time are charged the nominal transaction cost (12 drops), but the actual escrow cannot be cancelled until after the Escrow Cancel time.
## Oh No! I Forgot to Save the Sequence Number!
If you forget to save the sequence number, you can find it in the escrow transaction record.
1. Create a new escrow as described in [Create Escrow](#create-escrow), above.
2. Click **Get Escrows** to get the escrow information.
3. Copy the _PreviousTxnLgrSeq_ value from the results.
![Transaction ID in Get Escrows results](img/quickstart-py-conditional-escrow-5.png)
4. Paste the _PreviousTxnID_ in the **Transaction to Look Up** field.
![Transaction to Look Up field](img/quickstart-py-conditional-escrow-6.png)
5. Click **Get Transaction**.
6. Locate the _Sequence_ value in the results.
![Sequence number in results](img/quickstart-py-conditional-escrow-7.png)
# Code Walkthrough
You can download the [Modular Tutorials](https://github.com/XRPLF/xrpl-dev-portal/tree/master/content/_code-samples/quickstart/py/){.github-code-download} in the source repository for this website.
## getConditionAndFulfillment.js
To generate a condition/fulfillment pair, use Node.js to run the `getConditionAndFulfillment.js` script.
```javascript
function getConditionAndFulfillment() {
```
Instantiate the `five-bells-condition` and `crypto` libraries.
```javascript
const cc = require('five-bells-condition')
const crypto = require('crypto')
```
Create a random 32-byte seed string.
```javascript
const preimageData = crypto.randomBytes(32)
```
Create a fulfillment object.
```javascript
const fulfillment = new cc.PreimageSha256()
```
Generate a fulfillment code.
```javascript
fulfillment.setPreimage(preimageData)
```
Generate the condition value based on the fulfillment value.
```javascript
const condition = fulfillment.getConditionBinary().toString('hex').toUpperCase()
```
Return the condition.
```javascript
console.log('Condition:', condition)
```
Convert the fulfillment code to a hexadecimal string.
```javascript
const fulfillment_hex = fulfillment.serializeBinary().toString('hex').toUpperCase()
```
Return the fulfillment code. Keep it secret until you want to finish the escrow.
```javascript
console.log('Fulfillment:', fulfillment_hex)
}
getConditionAndFulfillment()
```
## mod9.py
Import dependencies.
```python
import xrpl
from xrpl.clients import JsonRpcClient
from xrpl.wallet import Wallet
from datetime import datetime
from xrpl.models.transactions import EscrowCreate, EscrowFinish
```
Create a global variable pointing to Testnet.
```python
testnet_url = "https://s.altnet.rippletest.net:51234"
```
### add_seconds
Create a date in the Ripple epoch, adding the specified number of seconds.
```python
def add_seconds(numOfSeconds):
```
Create a new_date variable.
```python
new_date = datetime.now()
```
Convert the date to a Ripple time object.
```python
if new_date != '':
new_date = xrpl.utils.datetime_to_ripple_time(new_date)
```
Add the requested seconds to the Ripple formatted date variable.
```python
new_date = new_date + int(numOfSeconds)
```
Return the result.
```python
return new_date
```
### create_conditional_escrow
You create conditional escrows using the same **EscrowCreate** model you used for a time-based escrow, but instead of a finish time, you provide a condition that must be met to complete the transaction.
Pass the _seed_ for the sending account, the _amount_ to hold in escrow, the _destination_ account to receive the escrow funds, the number of seconds until the escrow will _cancel_, and a _condition_ value that will be matched with a _fulfillment_ value to complete the escrow.
```python
def create_conditional_escrow(seed, amount, destination, cancel, condition):
```
Instantiate a wallet and connect to Testnet.
```python
wallet=Wallet.from_seed(seed)
client=JsonRpcClient(testnet_url)
```
Create a *cancel_date* variable, adding your specified number of seconds to the current Ripple epoch date.
```python
cancel_date = add_seconds(cancel)
```
Define the transaction with your provided values.
```python
escrow_tx=xrpl.models.transactions.EscrowCreate(
account=wallet.address,
amount=amount,
destination=destination,
cancel_after=cancel_date,
condition=condition
)
```
Submit the transaction and return the results.
```python
reply=""
try:
response=xrpl.transaction.submit_and_wait(escrow_tx,client,wallet)
reply=response.result
except xrpl.transaction.XRPLReliableSubmissionException as e:
reply=f"Submit failed: {e}"
return reply
```
### finish_conditional_escrow
At any time prior to the cancel date, the destination account can fulfill the escrow.
Pass the _seed_ for the receiving account, the _owner_ (sending account), the _sequence_ number for the escrow, the _condition_ value, and the matching _fulfillment_ value.
```python
def finish_conditional_escrow(seed, owner, sequence, condition, fulfillment):
```
Instantiate the account wallet and connect to Testnet.
```python
wallet=Wallet.from_seed(seed)
client=JsonRpcClient(testnet_url)
```
Define the **EscrowFinish** transaction, including both the condition and the fulfillment values.
```python
finish_tx=xrpl.models.transactions.EscrowFinish(
account=wallet.address,
owner=owner,
offer_sequence=int(sequence),
condition=condition,
fulfillment=fulfillment
)
```
Submit the transaction and report the results.
```python
reply=""
try:
response=xrpl.transaction.submit_and_wait(finish_tx,client,wallet)
reply=response.result
except xrpl.transaction.XRPLReliableSubmissionException as e:
reply=f"Submit failed: {e}"
return reply
```
## lesson9-conditional-escrow.py
This example builds on `lesson8-time-escrow.py` to reuse fields, buttons, and functions that apply to both time-based and conditional escrows. Updates are highlighted below.
```python
import tkinter as tk
import xrpl
import json
from mod1 import get_account, get_account_info, send_xrp
from mod8 import get_escrows, cancel_time_escrow, get_transaction
```
Import new functions for conditional escrows from module 9.
```python
from mod9 import create_conditional_escrow, finish_conditional_escrow
```
Add handlers for creating and finishing conditional escrows.
```python
def standby_create_conditional_escrow():
results = create_conditional_escrow(
ent_standby_seed.get(),
ent_standby_amount.get(),
ent_standby_destination.get(),
ent_standby_escrow_cancel.get(),
ent_standby_escrow_condition.get()
)
text_standby_results.delete("1.0", tk.END)
text_standby_results.insert("1.0", json.dumps(results, indent=4))
def operational_finish_conditional_escrow():
results = finish_conditional_escrow(
ent_operational_seed.get(),
ent_operational_escrow_owner.get(),
ent_operational_sequence_number.get(),
ent_standby_escrow_condition.get(),
ent_operational_escrow_fulfillment.get()
)
text_operational_results.delete("1.0", tk.END)
text_operational_results.insert("1.0", json.dumps(results, indent=4))
## Mod 8 Handlers
def operational_get_escrows():
results = get_escrows(ent_operational_account.get())
text_operational_results.delete("1.0", tk.END)
text_operational_results.insert("1.0", json.dumps(results, indent=4))
def standby_cancel_time_escrow():
results = cancel_time_escrow(
ent_standby_seed.get(),
ent_standby_escrow_owner.get(),
ent_standby_escrow_sequence_number.get()
)
text_standby_results.delete("1.0", tk.END)
text_standby_results.insert("1.0", json.dumps(results, indent=4))
def operational_get_transaction():
results = get_transaction(ent_operational_account.get(),
ent_operational_look_up.get())
text_operational_results.delete("1.0", tk.END)
text_operational_results.insert("1.0", json.dumps(results, indent=4))
## Mod 1 Handlers
def get_standby_account():
new_wallet = get_account(ent_standby_seed.get())
ent_standby_account.delete(0, tk.END)
ent_standby_seed.delete(0, tk.END)
ent_standby_account.insert(0, new_wallet.classic_address)
ent_standby_seed.insert(0, new_wallet.seed)
def get_standby_account_info():
accountInfo = get_account_info(ent_standby_account.get())
ent_standby_balance.delete(0, tk.END)
ent_standby_balance.insert(0,accountInfo['Balance'])
text_standby_results.delete("1.0", tk.END)
text_standby_results.insert("1.0",json.dumps(accountInfo, indent=4))
def standby_send_xrp():
response = send_xrp(ent_standby_seed.get(),ent_standby_amount.get(),
ent_standby_destination.get())
text_standby_results.delete("1.0", tk.END)
text_standby_results.insert("1.0",json.dumps(response.result, indent=4))
get_standby_account_info()
get_operational_account_info()
def get_operational_account():
new_wallet = get_account(ent_operational_seed.get())
ent_operational_account.delete(0, tk.END)
ent_operational_account.insert(0, new_wallet.classic_address)
ent_operational_seed.delete(0, tk.END)
ent_operational_seed.insert(0, new_wallet.seed)
def get_operational_account_info():
accountInfo = get_account_info(ent_operational_account.get())
ent_operational_balance.delete(0, tk.END)
ent_operational_balance.insert(0,accountInfo['Balance'])
text_operational_results.delete("1.0", tk.END)
text_operational_results.insert("1.0",json.dumps(accountInfo, indent=4))
def operational_send_xrp():
response = send_xrp(ent_operational_seed.get(),ent_operational_amount.get(),
ent_operational_destination.get())
text_operational_results.delete("1.0", tk.END)
text_operational_results.insert("1.0",json.dumps(response.result,indent=4))
get_standby_account_info()
get_operational_account_info()
# Create a new window with the title "Conditional Escrow Example"
window = tk.Tk()
window.title("Conditional Escrow Example")
# Form frame
frm_form = tk.Frame(relief=tk.SUNKEN, borderwidth=3)
frm_form.pack()
# Create the Label and Entry widgets for "Standby Account"
lbl_standy_seed = tk.Label(master=frm_form, text="Standby Seed")
ent_standby_seed = tk.Entry(master=frm_form, width=50)
lbl_standby_account = tk.Label(master=frm_form, text="Standby Account")
ent_standby_account = tk.Entry(master=frm_form, width=50)
lbl_standy_amount = tk.Label(master=frm_form, text="Amount")
ent_standby_amount = tk.Entry(master=frm_form, width=50)
lbl_standby_destination = tk.Label(master=frm_form, text="Destination")
ent_standby_destination = tk.Entry(master=frm_form, width=50)
lbl_standby_balance = tk.Label(master=frm_form, text="XRP Balance")
ent_standby_balance = tk.Entry(master=frm_form, width=50)
```
Add a field for the escrow condition.
```python
lbl_standby_escrow_condition = tk.Label(master=frm_form, text="Escrow Condition")
ent_standby_escrow_condition = tk.Entry(master=frm_form, width=50)
lbl_standby_escrow_cancel = tk.Label(master=frm_form, text="Escrow Cancel (seconds)")
ent_standby_escrow_cancel = tk.Entry(master=frm_form, width=50)
lbl_standby_escrow_sequence_number = tk.Label(master=frm_form, text="Sequence Number")
ent_standby_escrow_sequence_number = tk.Entry(master=frm_form, width=50)
lbl_standby_escrow_owner = tk.Label(master=frm_form, text="Escrow Owner")
ent_standby_escrow_owner = tk.Entry(master=frm_form, width=50)
lbl_standby_results = tk.Label(master=frm_form, text="Results")
text_standby_results = tk.Text(master=frm_form, height = 20, width = 65)
# Place fields in a grid.
lbl_standy_seed.grid(row=0, column=0, sticky="e")
ent_standby_seed.grid(row=0, column=1)
lbl_standby_account.grid(row=2, column=0, sticky="e")
ent_standby_account.grid(row=2, column=1)
lbl_standy_amount.grid(row=3, column=0, sticky="e")
ent_standby_amount.grid(row=3, column=1)
lbl_standby_destination.grid(row=4, column=0, sticky="e")
ent_standby_destination.grid(row=4, column=1)
lbl_standby_balance.grid(row=5, column=0, sticky="e")
ent_standby_balance.grid(row=5, column=1)
```
Insert the condition field in the standby grid.
```python
lbl_standby_escrow_condition.grid(row=6, column=0, sticky="e")
ent_standby_escrow_condition.grid(row=6, column=1)
lbl_standby_escrow_cancel.grid(row=7, column=0, sticky="e")
ent_standby_escrow_cancel.grid(row=7, column=1)
lbl_standby_escrow_sequence_number.grid(row=8, column=0, sticky="e")
ent_standby_escrow_sequence_number.grid(row=8, column=1)
lbl_standby_escrow_owner.grid(row=9, column=0, sticky="e")
ent_standby_escrow_owner.grid(row=9, column=1)
lbl_standby_results.grid(row=10, column=0, sticky="ne")
text_standby_results.grid(row=10, column=1, sticky="nw")
###############################################
## Operational Account ########################
###############################################
# Create the Label and Entry widgets for "Operational Account"
lbl_operational_seed = tk.Label(master=frm_form, text="Operational Seed")
ent_operational_seed = tk.Entry(master=frm_form, width=50)
lbl_operational_account = tk.Label(master=frm_form, text="Operational Account")
ent_operational_account = tk.Entry(master=frm_form, width=50)
lbl_operational_amount = tk.Label(master=frm_form, text="Amount")
ent_operational_amount = tk.Entry(master=frm_form, width=50)
lbl_operational_destination = tk.Label(master=frm_form, text="Destination")
ent_operational_destination = tk.Entry(master=frm_form, width=50)
lbl_operational_balance = tk.Label(master=frm_form, text="XRP Balance")
ent_operational_balance = tk.Entry(master=frm_form, width=50)
lbl_operational_sequence_number = tk.Label(master=frm_form, text="Sequence Number")
ent_operational_sequence_number = tk.Entry(master=frm_form, width=50)
lbl_operational_escrow_owner=tk.Label(master=frm_form, text="Escrow Owner")
ent_operational_escrow_owner=tk.Entry(master=frm_form, width=50)
lbl_operational_look_up = tk.Label(master=frm_form, text="Transaction to Look Up")
ent_operational_look_up = tk.Entry(master=frm_form, width=50)
```
Add a field for the escrow fulfillment value.
```python
lbl_operational_escrow_fulfillment = tk.Label(master=frm_form, text="Escrow Fulfillment")
ent_operational_escrow_fulfillment = tk.Entry(master=frm_form, width=50)
lbl_operational_results = tk.Label(master=frm_form,text='Results')
text_operational_results = tk.Text(master=frm_form, height = 20, width = 65)
#Place the widgets in a grid
lbl_operational_seed.grid(row=0, column=4, sticky="e")
ent_operational_seed.grid(row=0, column=5, sticky="w")
lbl_operational_account.grid(row=2,column=4, sticky="e")
ent_operational_account.grid(row=2,column=5, sticky="w")
lbl_operational_amount.grid(row=3, column=4, sticky="e")
ent_operational_amount.grid(row=3, column=5, sticky="w")
lbl_operational_destination.grid(row=4, column=4, sticky="e")
ent_operational_destination.grid(row=4, column=5, sticky="w")
lbl_operational_balance.grid(row=5, column=4, sticky="e")
ent_operational_balance.grid(row=5, column=5, sticky="w")
```
Insert the **Fulfillment** field in the operational grid, moving the other fields down so as to align the **Condition** and **Fulfillment** fields horizontally.
```python
lbl_operational_escrow_fulfillment.grid(row=6, column=4, sticky="e")
ent_operational_escrow_fulfillment.grid(row=6, column=5, sticky="w")
lbl_operational_sequence_number.grid(row=7, column=4, sticky="e")
ent_operational_sequence_number.grid(row=7, column=5, sticky="w")
lbl_operational_escrow_owner.grid(row=8, column=4, sticky="e")
ent_operational_escrow_owner.grid(row=8, column=5, sticky="w")
lbl_operational_look_up.grid(row=9, column=4, sticky="e")
ent_operational_look_up.grid(row=9, column=5, sticky="w")
lbl_operational_results.grid(row=10, column=4, sticky="ne")
text_operational_results.grid(row=10, column=5, sticky="nw")
#############################################
## Buttons ##################################
#############################################
# Create the Get Standby Account Buttons
btn_get_standby_account = tk.Button(master=frm_form, text="Get Standby Account",
command = get_standby_account)
btn_get_standby_account.grid(row = 0, column = 2, sticky = "nsew")
btn_get_standby_account_info = tk.Button(master=frm_form,
text="Get Standby Account Info",
command = get_standby_account_info)
btn_get_standby_account_info.grid(row = 1, column = 2, sticky = "nsew")
btn_standby_send_xrp = tk.Button(master=frm_form, text="Send XRP >",
command = standby_send_xrp)
btn_standby_send_xrp.grid(row = 2, column = 2, sticky = "nsew")
```
Add a **Create Conditional Escrow** button to the Standby grid.
```python
btn_standby_create_escrow = tk.Button(master=frm_form, text="Create Conditional Escrow",
command = standby_create_conditional_escrow)
btn_standby_create_escrow.grid(row = 4, column = 2, sticky="nsew")
btn_standby_cancel_escrow = tk.Button(master=frm_form, text="Cancel Escrow",
command = standby_cancel_time_escrow)
btn_standby_cancel_escrow.grid(row=5,column = 2, sticky="nsew")
# Create the Operational Account Buttons
btn_get_operational_account = tk.Button(master=frm_form,
text="Get Operational Account",
command = get_operational_account)
btn_get_operational_account.grid(row=0, column=3, sticky = "nsew")
btn_get_op_account_info = tk.Button(master=frm_form, text="Get Op Account Info",
command = get_operational_account_info)
btn_get_op_account_info.grid(row=1, column=3, sticky = "nsew")
btn_op_send_xrp = tk.Button(master=frm_form, text="< Send XRP",
command = operational_send_xrp)
btn_op_send_xrp.grid(row=2, column = 3, sticky = "nsew")
```
Add a **Finish Escrow** button to the operational grid.
```python
btn_op_finish_escrow = tk.Button(master=frm_form, text="Finish Escrow",
command = operational_finish_conditional_escrow)
btn_op_finish_escrow.grid(row = 4, column = 3, sticky="nsew")
btn_op_get_escrows = tk.Button(master=frm_form, text="Get Escrows",
command = operational_get_escrows)
btn_op_get_escrows.grid(row = 5, column = 3, sticky="nsew")
btn_op_get_transaction = tk.Button(master=frm_form, text="Get Transaction",
command = operational_get_transaction)
btn_op_get_transaction.grid(row = 6, column = 3, sticky = "nsew")
# Start the application
window.mainloop()
```

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@@ -1648,6 +1648,12 @@ pages:
- en
- ja
# TODO: translate
- md: tutorials/quickstart/py-create-conditional-escrows.md
targets:
- en
- ja
- name: NFTs Using Python
html: nfts-using-python.html
parent: modular-tutorials-in-python.html

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