pyC8 0.8.8

Python Driver for Macrometa Digital Edge Fabric

# PyC8

Welcome to the GitHub page for **pyC8**, a Python driver for the Digital Edge Fabric.

### Features


- Clean Pythonic interface.
- Lightweight.

### Compatibility

- Python versions 3.4, 3.5 and 3.6 are supported.

### Build & Install

To build,

```bash
$ python setup.py build
```
To install locally,

```bash
$ python setup.py build
```

### Getting Started

Here is an overview example:

```python
from c8 import C8Client
import time
import warnings
warnings.filterwarnings("ignore")

region = "qa1-us-east-1.ops.aws.macrometa.io"
demo_tenant = "demotenant"
demo_db = "demodb"
demo_user = "demouser"
demo_collection = "employees"
demo_stream = "demostream"

#--------------------------------------------------------------
print("Create demo tenant...")
client = C8Client(protocol='https', host=region, port=443)
sys_tenant = client.tenant(name='_mm', dbname='_system', username='root', password='poweruser')

if not sys_tenant.has_tenant(demo_tenant):
sys_tenant.create_tenant(demo_tenant, passwd="poweruser")

#--------------------------------------------------------------
print("Create under demotenant, demodb, demouser and assign permissions...")
demotenant = client.tenant(name=demo_tenant, dbname='_system', username='root', password='poweruser')

if not demotenant.has_user(demo_user):
demotenant.create_user(username=demo_user, password='demouser', active=True)

if not demotenant.has_database(demo_db):
demotenant.create_database(name=demo_db, dclist=demotenant.dclist(), realtime=True)

demotenant.update_permission(username=demo_user, permission='rw', database=demo_db)

#--------------------------------------------------------------
print("Create and populate employees collection in demodb...")
db = client.db(tenant=demo_tenant, name=demo_db, username=demo_user, password='demouser')
employees = db.create_collection('employees') # Create a new collection named "employees".
employees.add_hash_index(fields=['email'], unique=True) # Add a hash index to the collection.

employees.insert({'firstname': 'Jean', 'lastname':'Picard', 'email':'[e-mail]'})
employees.insert({'firstname': 'James', 'lastname':'Kirk', 'email':'[e-mail]'})
employees.insert({'firstname': 'Han', 'lastname':'Solo', 'email':'[e-mail]'})
employees.insert({'firstname': 'Bruce', 'lastname':'Wayne', 'email':'[e-mail]'})

#--------------------------------------------------------------
print("query employees collection...")
cursor = db.c8ql.execute('FOR employee IN employees RETURN employee') # Execute a C8QL query
docs = [document for document in cursor]
print(docs)

#--------------------------------------------------------------
print("Create global & local streams in demodb...")
db.create_stream(demo_stream, persistent=True, local=False)
db.create_stream(demo_stream, persistent=True, local=True)
db.create_stream(demo_stream, persistent=False, local=False)
db.create_stream(demo_stream, persistent=False, local=True)
streams = db.streams()
print("streams:", streams)

#--------------------------------------------------------------
#sys_tenant.delete_tenant(demo_tenant)

```

Example to **query** a given database:

```python

from c8 import C8Client
import json
import warnings
warnings.filterwarnings("ignore")

region = "qa1-us-east-1.ops.aws.macrometa.io"

#--------------------------------------------------------------
print("query employees collection...")
client = C8Client(protocol='https', host=region, port=443)
db = client.db(tenant="demotenant", name="demodb", username="demouser", password='poweruser')
cursor = db.c8ql.execute('FOR employee IN employees RETURN employee') # Execute a C8QL query
docs = [document for document in cursor]
print(docs)

```

Example for **real-time updates** from a collection in database:

```python

from c8 import C8Client
import warnings
warnings.filterwarnings("ignore")

region = "qa1-us-east-1.ops.aws.macrometa.io"

def callback_fn(event):
print(event)

#--------------------------------------------------------------
print("Subscribe to employees collection...")
client = C8Client(protocol='https', host=region, port=443)
db = client.db(tenant="demotenant", name="demodb", username="demouser", password='poweruser')
db.on_change(collection="employees", callback=callback_fn)

```

Example to **publish** documents to a stream:

```python

from c8 import C8Client
import time
import warnings
warnings.filterwarnings("ignore")

region = "qa1-us-east-1.ops.aws.macrometa.io"

#--------------------------------------------------------------
print("publish messages to stream...")
client = C8Client(protocol='https', host=region, port=443)
db = client.db(tenant="demotenant", name="demodb", username="demouser", password='poweruser')
producer = db.stream().create_producer(collection="demostream", persistent=True, local=False)
for i in range(10):
producer.send(b"Hello from " + region + "("+ i +")")
time.sleep(1) #sec

```

Example to **subscribe** documents from a stream:

```python

from c8 import C8Client
import warnings
warnings.filterwarnings("ignore")

region = "qa1-us-east-1.ops.aws.macrometa.io"

#--------------------------------------------------------------
print("consume messages from stream...")
client = C8Client(protocol='https', host=region, port=443)
db = client.db(tenant="demotenant", name="demodb", username="demouser", password='poweruser')
subscriber = db.stream().subscribe(collection="demostream", persistent=True, local=False, subscription_name="demosub")
subscriber.receive()

```

Here is another example with **graphs**:

```python

from c8 import C8Client

# Initialize the client for C8DB.
client = C8Client(protocol='http', host='localhost', port=8529)

# Connect to "test" database as root user.
db = client.db('test', username='root', password='passwd')

# Create a new graph named "school".
graph = db.create_graph('school')

# Create vertex collections for the graph.
students = graph.create_vertex_collection('students')
lectures = graph.create_vertex_collection('lectures')

# Create an edge definition (relation) for the graph.
register = graph.create_edge_definition(
edge_collection='register',
from_vertex_collections=['students'],
to_vertex_collections=['lectures']
)

# Insert vertex documents into "students" (from) vertex collection.
students.insert({'_key': '01', 'full_name': 'Anna Smith'})
students.insert({'_key': '02', 'full_name': 'Jake Clark'})
students.insert({'_key': '03', 'full_name': 'Lisa Jones'})

# Insert vertex documents into "lectures" (to) vertex collection.
lectures.insert({'_key': 'MAT101', 'title': 'Calculus'})
lectures.insert({'_key': 'STA101', 'title': 'Statistics'})
lectures.insert({'_key': 'CSC101', 'title': 'Algorithms'})

# Insert edge documents into "register" edge collection.
register.insert({'_from': 'students/01', '_to': 'lectures/MAT101'})
register.insert({'_from': 'students/01', '_to': 'lectures/STA101'})
register.insert({'_from': 'students/01', '_to': 'lectures/CSC101'})
register.insert({'_from': 'students/02', '_to': 'lectures/MAT101'})
register.insert({'_from': 'students/02', '_to': 'lectures/STA101'})
register.insert({'_from': 'students/03', '_to': 'lectures/CSC101'})

# Traverse the graph in outbound direction, breadth-first.
result = graph.traverse(
start_vertex='students/01',
direction='outbound',
strategy='breadthfirst'
)
```

Example for **Stream Collections**:

```python
from c8 import C8Client

# Initialize the client for C8DB.
client = C8Client(protocol='http', host='localhost', port=8529)

sys_tenant = client.tenant(name='_mm', dbname='_system', username='root', password='poweruser')

# Connect to "_system" database as root user.
sys_db = client.db(name='_system', username='root', password='poweruser')

#Create a new global persistent stream called test-stream. If persistent flag set to False,
# a non-persistent stream gets created. Similarly a local stream gets created if local
# flag is set to True. By default persistent is set to True and local is set to False .
sys_db.create_stream('test-stream', persistent=True, local=False)

#List all persistent/non-persistent and global/local streams
streams = sys_db.streams()

#Create producer for the given persistent/non-persistent and global/local stream.
stream_collection = sys_db.stream()
producer = stream_collection.create_producer('test-stream', persistent=True, local=False)

#Send: is a plusar method that publish/sends a given message over stream in byte's.
producer.send(b"Hello")

#Create a subscriber to the given persistent/non-persistent and global/local stream with the given,
# subscription name. If no subscription new is provided then a random name is generated. based on
# tenant and db information
subscriber = stream_collection.subscribe('test-stream', persistent=True, local=False, subscription_name="test-subscription")

#receive: is a plusar function to read the published messages over stream.
subscriber.receive()

#Delete a given persistent/non-persistent and global/local stream.
sys_db.delete_stream('test-stream', persistent=True, local=False)
```