Test-Driven Python Development

Understanding the code

The following is the code that we are going to be looking at in this chapter:

from datetime import datetime from .stock import Stock from .rule import PriceRule class AlertProcessor: def __init__(self): self.exchange = {"GOOG": Stock("GOOG"), "AAPL": Stock("AAPL")} rule_1 = PriceRule("GOOG", lambda stock: stock.price > 10) rule_2 = PriceRule("AAPL", lambda stock: stock.price > 5) self.exchange["GOOG"].updated.connect( lambda stock: print(stock.symbol, stock.price) \ if rule_1.matches(self.exchange) else None) self.exchange["AAPL"].updated.connect( lambda stock: print(stock.symbol, stock.price) \ if rule_2.matches(self.exchange) else None) updates = [] with open("updates.csv", "r") as fp: for line in fp.readlines(): symbol, ...