How to create a Stock instance?

To create a Stock instance, you can use the following code:

from validate import String, PositiveInteger, PositiveFloat
from structure import typed_structure

# Create a Stock class with type validation
Stock = typed_structure('Stock', name=String(), shares=PositiveInteger(), price=PositiveFloat())

# Create a stock instance
s = Stock('GOOG', 100, 490.1)

# Test the instance
print(s.name)  # Output: GOOG
print(s)       # Output: Stock('GOOG', 100, 490.1)

In this example, we first import the necessary validators and create a Stock class with type validation. Then, we create an instance of the Stock class by providing the stock name, number of shares, and price. Finally, we print the stock name and the instance itself.