Crea Developer Portal
How to pull a list of the active user accounts or popular tags from the blockchain using Python.
This tutorial will explain and show you how to access the Crea blockchain using the crea-python library to fetch a list of active authors or popular tags, starting the search from a specified value, and displaying the results on the console.
We are using the
get_popular_tags functions that are built-in in the official library
crea-python. These functions allow us to query the Crea blockchain in order to retrieve either a list of active authors or a list of popular tags. The option is available to either get a complete list starting from the first value on the blockchain or starting the list from any other closest match string value as provided by the user. Both of these functions have only two parameters:
- account/aftertag - The string value from where to start the search. If this value is left empty the search will start from the first value available
- limit - The maximum number of names/tags that the query retrieves
- App setup - Library import and Crea class initialisation
- List selection - Selection of the type of list
- Get and display account names - Get a list of account names from the blockchain
- Get and display popular tags - Get a list of popular tags from the blockchain
In this tutorial we use 2 packages,
pick - helps us to select the query type interactively.
crea - crea-python library for interaction with the Blockchain.
First we import both libraries and initialize Crea class
from crea import Crea from pick import pick s = Crea()
The user is given the option of which list to create,
active accounts or
popular tags. We create this option list and setup
#choose list type title = 'Please select type of list:' options = ['Active Account names', 'Popular tags'] #get index and selected list name option, index = pick(options, title)
This will show the two options as a list to select in terminal/command prompt. From there we can determine which function to execute.
Once the user selects the required list, a simple
if statement is used to execute the relevant function. Based on the selection we then run the query. The parameters for the
lookup_accounts function is captured in the
if statement via the terminal/console.
if option=='Active Account names' : #capture starting account account = input("Enter account name to start search from: ") #input list limit limit = input("Enter max number of accounts to display: ") lists = s.lookup_accounts(account, limit) print('\n' + "List of " + option + '\n') print(*lists, sep='\n')
Once the list is generated it is displayed on the UI with line separators along with a heading of what list it is.
The query for a list of popular tags is executed in the second part of the
if statement. Again, the parameters for the query is captured via the terminal/console.
else : #capture starting tag aftertag = input("Enter tag name to start search from: ") #capture list limit limit = input("Enter max number of tags to display: ") lists = s.get_popular_tags(aftertag, limit) print('\n' + "List of " + option + '\n') for names in lists : print(names["name"])
The query returns an array of objects. We use the
for loop to build a list of only the tag
names from that array and then display the list on the UI with line separators. This creates an easy to read list of tags.
To Run the tutorial
- review dev requirements
- clone this repo
pip install -r requirements.txt
- After a few moments, you should see output in terminal/command prompt screen.