datacursor_example_lookup.py

import random
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

def main():
    accounts = generate_accounts()
    lookup = plot(accounts)
    datacursor(formatter=Formatter(lookup), bbox=dict(alpha=1))
    plt.show()

def plot(accounts):
    lookup = {}
    fig, ax = plt.subplots()
    for i, account in enumerate(accounts):
        artist, = ax.bar([i], [account.balance], align='center')
        lookup[artist] = account

    ax.set(xticks=[], ylabel='Balance ($)')
    ax.grid(axis='y')

    return lookup

def generate_accounts():
    names = ['Mark', 'Nancy', 'Sam', 'John', 'Patricia', 'Anna']
    accounts = [random.randint(100000, 9999999) for _ in names]
    balances = [random.randint(-1000, 10000) for _ in names]
    return [BankAccount(*item) for item in zip(names, accounts, balances)]

class BankAccount:
    def __init__(self, owner, number, balance):
        self.owner, self.number, self.balance = owner, number, balance

class Formatter:
    def __init__(self, account_lookup):
        self.account_lookup = account_lookup

    def __call__(self, **kwargs):
        artist = kwargs['event'].artist
        account = self.account_lookup[artist]

        template = 'Owner: {}\nAccount: {}\nBalance: {}'
        return template.format(account.owner, account.number, account.balance)

main()