Python Type Conversion: Implicit Conversion and Explicit Casting

All flashcards

What is implicit type conversion?

It is an automatic conversion Python makes when a compatible operation needs values to work with a common type. For example, adding an integer and a float produces a float.

What does int() do when given a float?

It converts the float to an integer by removing the fractional part, not by rounding to the nearest integer. For example, int(5.9) returns 5.

What do float() and str() do?

float(value) converts a compatible value to a floating-point number, while str(value) converts it to text. For example, float(2) is 2.0 and str(3.14) is '3.14'.

Why must input often be converted before arithmetic?

input() returns a string. Convert the returned text to int or float before using it in numeric calculations.

How can a program calculate cups drank and cups left from ounces?

Convert the input to an integer, divide ounces by 8.0 to get cups_drank as a float, and convert 8 minus cups_drank to int for cups_left.

Quiz questions

1. What happens when a Python variable is assigned a value of a different type from its previous value?Answer: It refers to the newly assigned value, which can have a different type.
2. What does int(-2.9) return in Python?Answer: -2
3. What happens when a Python expression tries to add a number directly to a string?Answer: The operation usually raises a TypeError.
4. What value and type result from calling float(2) in Python?Answer: The floating-point value 2.0.
5. Which sequence converts two input strings to integers before multiplying them, then converts the product to a float?Answer: Apply int() to each input, multiply the results, then apply float() to the product.