retsdk 1.0.2

Python SDK for the real estate transaction standard (RETS)

RETSDK

A Python SDK for the Real Estate Transaction Standard (RETS)

Installation

pip install retsdk

Usage

Initialize a client

Create a new RETSConnection instance to connect to a RETS server.

Example

from retsdk.client import RETSConnection

rets = RETSConnection(
    username='your_rets_username',
    password='your_rets_password',
    login_url='https://rets.somemls.com/rets/Login/'
)

# Metadata info & transaction URLs get loaded automatically
print(rets.metadata_version)
# 1.00.00235

print(rets.metadata_timestamp)
# 2015-05-20T20:08:15Z

print(rets.min_metadata_timestamp)
# 2015-05-20T20:08:15Z

print(rets.get_metadata_url)
# https://rets.somemls.com/rets/GetMetadata/

print(rets.get_search_url)
# https://rets.somemls.com/rets/Search/

print(rets.get_object_url)
# https://rets.somemls.com/rets/GetObject/

Initialization Arguments

Argument	Type	Required	Meaning
username	String	Yes	RETS account username
password	String	Yes	RETS account password
login_url	String	Yes	RETS server login URL
auth_type	String	No	Authentication type (defaults to 'digest')
rets_version	String	No	Specifies the RETS version to be used (defaults to 'RETS/1.7.2')
user_agent	String	No	Specifies the user-agent (defaults to 'RETSDK/1.0')

Download Metadata

There are (usually) several tiers of metadata to consider in a RETS system. These are resource metadata, class metadata, table metadata, and lookup-type metadata. RETSDK has methods to work with each of these programmatically, but if you would like to view metadata right in your browser with no additional setup, you can also try RETSMD.

All of the metadata query methods return a response dictionary with the following items:

Key	Meaning	Value
more_rows	Indicates whether there are more rows to download	Boolean
ok	Indicates whether the process completed successfully	Boolean
record_count	The number of rows returned	Integer
reply_code	The server's RETS reply code	Integer
reply_text	The message accompanying the RETS reply code	String
rows	The metadata records returned by the server	List

1. Resource Metadata

Resource metadata is the top layer of metadata; it tells you what resources are accessible from your account. Use the get_resource_metadata() method to download resource metadata.

Arguments

None

Example

# Get the RETS system's resource metadata
response = rets.get_resource_metadata()

from pprint import pprint
pprint(response)
#{'more_rows': False,
# 'ok': True,
# 'record_count': 2,
# 'reply_code': '0',
# 'reply_text': 'Operation Success.',
# 'rows': [{'ClassCount': 1,
#           'ClassDate': '2015-01-28T21:06:04Z',
#           'ClassVersion': '1.00.00001',
#           'Description': 'Agent',
#           'KeyField': 'sysid',
#           'LookupDate': '2015-01-21T17:31:54Z',
#           'LookupVersion': '1.00.00001',
#           'ObjectDate': '2014-03-21T17:15:24Z',
#           'ObjectVersion': '1.00.00001',
#           'ResourceID': 'Agent',
#           'StandardName': 'Agent',
#           'TableName': 'Agent',
#           'VisibleName': 'Agent'},
#          {'ClassCount': 1,
#           'ClassDate': '2015-01-28T16:19:02Z',
#           'ClassVersion': '1.00.00001',
#           'Description': 'Listing',
#           'KeyField': 'sysid',
#           'LookupDate': '2015-01-28T14:34:35Z',
#           'LookupVersion': '1.00.00001',
#           'ObjectDate': '2015-01-28T14:34:35Z',
#           'ObjectVersion': '1.00.00001',
#           'ResourceID': 'Property',
#           'StandardName': 'Property',
#           'TableName': 'Listing',
#           'VisibleName': 'Listing'}]}

2. Class Metadata

Class metadata provides information about the classes in a resource. Use the get_class_metadata() method to get class metadata.

Arguments

Argument Name	Required	Meaning
resource	No	The ID of a RETS resource. Defaults to 'Property'.

Example

class_metadata_response = rets.get_class_metadata(resource='Property')

pprint(class_metadata_response)
#{'more_rows': False,
# 'ok': True,
# 'record_count': 1,
# 'reply_code': '0',
# 'reply_text': 'Operation Success.',
# 'rows': [{'ClassName': 'Listing',
#           'Description': 'Cross Property',
#           'StandardName': None,
#           'TableDate': '2015-01-28T02:49:39Z',
#           'TableVersion': '1.00.00985',
#           'UpdateDate': '2015-01-28T14:32:06Z',
#           'UpdateVersion': '1.00.00001',
#           'VisibleName': 'Cross Property'}]}

3. Table Metadata

Table metadata tells you about the specific fields available in a class. Use the get_table_metadata() method to get table metadata.

Arguments

Argument Name	Required	Meaning
resource	No	The ID of a resource. Defaults to 'Property'.
class_name	No	The class name or system name of a class within a resource. Defaults to 'Listing'.

Example

table_metadata_response = rets.get_table_metadata(
    resource='Property', 
    class_name='Listing'
)

pprint(table_metadata_response)
#{'more_rows': False,
# 'ok': True,
# 'record_count': 2,
# 'reply_code': '0',
# 'reply_text': 'Operation Success.',
# 'rows': [{'Alignment': 'Left',
#           'DBName': 'price',
#           'DataType': 'Int',
#           'Default': None,
#           'InKeyIndex': 0,
#           'Index': 1,
#           'Interpretation': 'Number',
#           'LongName': 'Price',
#           'LookupName': None,
#           'MaxSelect': None,
#           'Maximum': 2147483647,
#           'MaximumLength': 11,
#           'MetadataEntryID': 200,
#           'Minimum': -2147483648,
#           'Precision': None,
#           'Required': 1,
#           'Searchable': 1,
#           'ShortName': 'Price',
#           'StandardName': 'Price',
#           'SystemName': 'Price',
#           'Unique': 0,
#           'Units': 'USD',
#           'UseSeparator': None},
#          {'Alignment': 'Left',
#           'DBName': 'property_type',
#           'DataType': 'Character',
#           'Default': None,
#           'InKeyIndex': 0,
#           'Index': 1,
#           'Interpretation': 'Lookup',
#           'LongName': 'Property Type',
#           'LookupName': 'PropertyType',
#           'MaxSelect': None,
#           'Maximum': None,
#           'MaximumLength': 32,
#           'MetadataEntryID': 201,
#           'Minimum': None,
#           'Precision': None,
#           'Required': 1,
#           'Searchable': 1,
#           'ShortName': 'PropertyType',
#           'StandardName': 'PropertyType',
#           'SystemName': 'PropertyType',
#           'Unique': 0,
#           'Units': None,
#           'UseSeparator': None}]}

4. Lookup-Type Metadata

The last type of metadata data to consider is lookup-type metdata. If a field in the table metadata has an interpretation of "Lookup", there is a list of specific values that the field can hold. Get this list of values with the get_lookup_type_metadata() method.

Arguments

Argument Name	Required	Meaning
resource	No	The ID of a resource. Defaults to 'Property'.
lookup_name	Yes	A field's lookup name.

Example

lookup_type_metadata_response = rets.get_lookup_type_metadata(
    resource='Property',
    lookup_name='PropertyType'
)

pprint(lookup_type_metadata_response)
# {'more_rows': False,
#  'ok': True,
#  'record_count': 3,
#  'reply_code': '0',
#  'reply_text': 'Operation Success.',
#  'rows': [{'LongValue': 'Single Family Detached',
#           'MetadataEntryID': 10002,
#           'ShortValue': 'SFD',
#           'Value': 'SFD'},
#          {'LongValue': 'Condominium',
#           'MetadataEntryID': 10003,
#           'ShortValue': 'CON',
#           'Value': 'CON'},
#          {'LongValue': 'Multifamily',
#           'MetadataEntryID': 10004,
#           'ShortValue': 'MUL',
#           'Value': 'MUL'}]}

Download Data

Download data or search through records using the get_data() method. You will need to specify a query (using DMQL) and a list of the fields that you would like to have returned to you (see Download Metadata to learn how to find out what fields are available).

Arguments

Argument Name	Required	Meaning
resource	Yes	The ID of a RETS system resource.
class_name	Yes	The name of a class in the specified resource.
query	Yes	A DMQL query
fields	Yes	A list of the fields to be returned
data_format	No	The RETS data format to be used with fields. Defaults to 'COMPACT-DECODED'.
limit	No	The maximum number of records to return
offset	No	An offset position that can be used with limit

Response Dictionary

Key	Meaning	Value Type
more_rows	Indicates whether there are more rows to download for the current query	Boolean
ok	Indicates whether the query was processed successfully	Boolean
record_count	The number of rows returned	Integer
reply_code	The server's RETS reply code	Integer
reply_text	The message accompanying the RETS reply code	String
rows	The actual records returned by the query	List

Examples

# Query all listings with "SFD" PropertyType, return only MLSNumber and Price
rets_query = "(PropertyType=SFD)"
fields_to_be_downloaded = ["MLSNumber", "Price"]

data = rets.get_data(
    resource='Property',
    class_name='Property',
    query=query,
    fields=fields_to_be_downloaded,
)

pprint(data)
# {'more_rows': False,
#  'ok': True,
#  'record_count': '10',
#  'reply_code': '0',
#  'reply_text': 'Operation Success.',
#  'rows': [{'Price': 199000.0, 'MLSNumber': 'MLS0000001'},
#           {'Price': 2500000.0, 'MLSNumber': 'MLS0000002'},
#           {'Price': 319500.0, 'MLSNumber': 'MLS0000003'},
#           {'Price': 275900.0, 'MLSNumber': 'MLS0000004'},
#           {'Price': 239900.0, 'MLSNumber': 'MLS0000005'},
#           {'Price': 339900.0, 'MLSNumber': 'MLS0000006'},
#           {'Price': 249900.0, 'MLSNumber': 'MLS0000007'},
#           {'Price': 219900.0, 'MLSNumber': 'MLS0000008'},
#           {'Price': 579900.0, 'MLSNumber': 'MLS0000009'},
#           {'Price': 209900.0, 'MLSNumber': 'MLS0000010'}]}

You may optionally use the limit and offset parameters to page the data that you want to download. This allows you to break large downloads into smaller pieces.

# A broader RETS query that might returns lots of records
rets_query=(PropertyType=SFD,CON,MUL)
fields_to_be_downloaded = ["MLSNumber", "Price"]

# Use a loop to download 10 records at a time
download_complete = False
last_offset = 0
while not download_complete:
    data = rets.get_data(
        resource='Property',
        class_name='Listing',
        query=rets_query,
        fields=fields_to_be_downloaded,
        limit=10,
        offset=last_offset
    )

    for row in data['rows']:
        # Do something with the rows you downloaded here (save to a database, etc.)
        pass

    if data['more_rows']:
        # Still more to download!
        last_offset += 10
    else:
        # Done!
        download_complete = True

Getting a Record Count without Returning Data

If you just want a count of how many records match your query, you can use get_count() instead of get_data(). get_count() will return an integer instead of a full response dictionary.

You do not specify fields, limit, or offset with get_count(), but otherwise it works just like get_data(). It is, in fact, just another wrapper for the RETS Search transaction with the Count parameter set differently.

Example

row_count = rets.get_count(
    'Property',
    class_name='Property',
    query=rets_query
)

print(row_count)
# 105

Download Images

Use the get_object() method to download images. This method is a wrapper for the RETS specification's GetObject transaction.

get_object() returns a response dictionary, but the dictionary does not contain 'rows', 'record_count' or 'more_rows'. Instead, it will contain an item called 'object_data', where the actual object data will be stored as bytes.

Arguments

Argument Name	Required	Meaning
resource	Yes	The ID of a RETS system resource.
obj_type	Yes	The type of object to be returned (e.g., 'Photo').
obj_id	Yes	The system ID of the record associated with object.
order_no	No	The order number of the image or other object (for situations where there are multiple images associated with one listing)
path	No	A file system path where image data should be written (used only when write=True).
write	No	A boolean value that can optionally be set to True if you would like get_object() to write image/object data to a file for you. You must specifiy a path if you wish to use this option.

Response Dictionary:

Key	Meaning	Value Type
ok	Indicates whether the object download was successful	Boolean
reply_code	The server's RETS reply code	Integer
reply_text	The message accompanying the RETS reply code	String
object_data	The object data payload	Bytes

Example

# Download an image (as bytes)
img_response = rets.get_object(
    resource='Property',
    obj_type='Photo',
    obj_id='MLS0000001',
    order_no=0
)

# Write the image data to a file somewhere
path = "/tmp/rets/images/MLS0000001_01.jpg"
if img_response['ok']:
    with open(path, 'wb') as f:
        f.write(img_response['object_data'])

Logout

If you would like to, you can close your RETS session with the logout() method.

Arguments

None

Response Dictionary:

Key	Meaning	Value Type
more_rows	Indicates whether there are more rows to download for the current transaction	Boolean
ok	Indicates whether the transaction was successful	Boolean
record_count	The number of rows returned	Integer
reply_code	The server's RETS reply code	Integer
reply_text	The message accompanying the RETS reply code	String
rows	The actual records returned by the logout transaction	List

Example

logout_response = rets.logout()

pprint(logout_response)
# {'more_rows': False,
#  'ok': True,
#  'record_count': 1,
#  'reply_code': '0',
#  'reply_text': 'Operation Success.',
#  'rows': [{'SignOffMessage': 'Connection Closed'}]}

Exceptions

RETSDK raises these exceptions when stuff goes wrong:

Exception	Meaning
retsdk.exceptions.AuthenticationError	Raised when an unsupported authentication type is specified during intialization
retsdk.exceptions.RequestError	Raised if a RETS transaction request cannot be completed
retsdk.exceptions.TransactionError	Raised if the user attempts to perform a transaction that is not supported by the current RETS account.