pyC8 0.10.5

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_fabric = "demofabric"
demo_user = "demouser"
demo_collection = "employees"
demo_stream = "demostream"

#--------------------------------------------------------------
print("Create C8Client Connection...")
client = C8Client(protocol='https', host=region, port=443)

#--------------------------------------------------------------
print("Create under demotenant, demofabric, demouser and assign permissions...")
demotenant = client.tenant(name=demo_tenant, fabricname='_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_fabric(demo_fabric):
demotenant.create_fabric(name=demo_fabric, dclist=demotenant.dclist())

demotenant.update_permission(username=demo_user, permission='rw', fabric=demo_fabric)

#--------------------------------------------------------------
print("Create and populate employees collection in demofabric...")
fabric = client.fabric(tenant=demo_tenant, name=demo_fabric, username=demo_user, password='demouser')
#get fabric detail
fabric.fabrics_detail()
employees = fabric.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 = fabric.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 demofabric...")
fabric.create_stream(demo_stream, local=False)
fabric.create_stream(demo_stream, local=True)

streams = fabric.streams()
print("streams:", streams)

#--------------------------------------------------------------

```

Example to **query** a given fabric:

```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)
fabric = client.fabric(tenant="demotenant", name="demofabric", username="demouser", password='poweruser')
cursor = fabric.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 fabric:

```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)
fabric = client.fabric(tenant="demotenant", name="demofabric", username="demouser", password='poweruser')
fabric.on_change("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)
fabric = client.fabric(tenant="demotenant", name="demofabric", username="demouser", password='poweruser')
stream = fabric.stream()
producer = stream.create_producer("demostream", local=False)
for i in range(10):
msg = "Hello from " + region + "("+ str(i) +")"
producer.send(msg.encode('utf-8'))
time.sleep(10) # 10 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)
fabric = client.fabric(tenant="demotenant", name="demofabric", username="demouser", password='poweruser')
stream = fabric.stream()
#you can subscribe using consumer_types option.
subscriber = stream.subscribe("demostream", local=False, subscription_name="demosub", consumer_type= stream.CONSUMER_TYPES.EXCLUSIVE)
for i in range(10):
msg = subscriber.receive()
print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
subscriber.acknowledge(msg)

```

Example: **stream management**:

```python

stream_collection = fabric.stream()
#get_stream_stats
stream_collection.get_stream_stats('demostream', local=False) #for global persistent stream

#Skip all messages on a stream subscription
stream_collection.skip_all_messages_for_subscription('demostream', 'demosub')

#Skip num messages on a topic subscription
stream_collection.skip_messages_for_subscription('demostream', 'demosub', 10)

#Expire messages for a given subscription of a stream.
#expire time is in seconds
stream_collection.expire_messages_for_subscription('demostream', 'demosub', 2)

#Expire messages on all subscriptions of stream
stream_collection.expire_messages_for_subscriptions('demostream',2)

#Reset subscription to message position to closest timestamp
#time is in milli-seconds
stream_collection.reset_message_subscription_by_timestamp('demostream','demosub', 5)

#Reset subscription to message position closest to given position
#stream_collection.reset_message_for_subscription('demostream', 'demosub')

#stream_collection.reset_message_subscription_by_position('demostream','demosub', 4)

#trigger compaction status
stream_collection.put_stream_compaction_status('demostream')

#get stream compaction status
stream_collection.get_stream_compaction_status('demostream')

#Unsubscribes the given subscription on all streams on a stream fabric
stream_collection.unsubscribe('demosub')

#delete subscription of a stream
#stream_collection.delete_stream_subscription('demostream', 'demosub' , local=False)

```

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" fabric as root user.
fabric = client.fabric('test', username='root', password='passwd')

# Create a new graph named "school".
graph = fabric.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'
)
```

Workflow of **Spot Collections**

```python

from c8 import C8Client

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

#Step 1: Make one of the regions in the fed as the Spot Region
# Connect to System admin
sys_tenant = client.tenant(name=macrometa-admin, fabricname='_system', username='root', password=macrometa-password)
#Make REGION-1 as spot-region
sys_tenant.assign_dc_spot('REGION-1',spot_region=True)

#Make REGION-2 as spot-region
sys_tenant.assign_dc_spot('REGION-2',spot_region=True)

#Step 2: Create a geo-fabric and pass one of the spot regions. You can use the SPOT_CREATION_TYPES for the same. If you use AUTOMATIC, a random spot region will be assigned by the system.
# If you specify None, a geo-fabric is created without the spot properties. If you specify spot region,pass the corresponding spot region in the spot_dc parameter.
dcl = sys_tenant.dclist()
fabric = client.fabric(tenant='guest', name='_system', username='root', password='guest')
fabric.create_fabric('spot-geo-fabric', dclist=dcl,spot_creation_type= fabric.SPOT_CREATION_TYPES.SPOT_REGION, spot_dc='REGION-1')

#Step 3: Create spot collection in 'spot-geo-fabric'
spot_collection = fabric.create_collection('spot-collection', spot_collection=True)

#Step 4: Update Spot primary region of the geo-fabric. To change it, we need system admin credentials
sys_fabric = client.fabric(tenant=macrometa-admin, name='_system', username='root', password=macrometa-password)
sys_fabric.update_spot_region('guest', 'spot-geo-fabric', 'REGION-2')

```