In Python, you can convert from one variable type to another using type casting. Type casting is the process of changing the data type of a variable from one type to another. This may be useful if you are trying to manipulate or extract more specific information from a variable. Here are some ways to perform type casting in Python.
To convert a variable to an integer, you can use the int() function. Note that this will always round the value down if it is passed in as a float. For example:
x = 3.14 y = int(x) # y will be 3 cost = 19.99 newCost = int(cost) # this will round the value down to 19 ageString = "27" ageInt = int(ageString) # will return just 27, without the quotations
To convert a variable to a float, you can use the float() function. For example:
x = 42 y = float(x) # y will be 42.0
To convert a variable to a string, you can use the str() function. For example:
pi = 3.14159 x = str(pi) # x will be "3.14159"
To convert a variable to a boolean, you can use the bool() function. Note that if the numeric value 0 is passed into bool() function, it will return False, while everything returns True. This may not sound like a very intuitive function to use, but there may be given instances that we see later on where this may helpful. For example:
a = 0 b = bool(a) # b will be False c = 25 d = bool(c) # c will be True (non-zero) e = "Hello World" f = bool(f) # f will be True (non-zero)
Note that not all conversions are possible or meaningful. For example, converting a string that contains non-numeric characters to an integer or a float will result in a ValueError. For example:
name = "John" x = int(name) # results in a ValueError because name contains characters
At any given time, you can check the type of a variable by simply using the type() function and passing the variable inside the parentheses:
name = "John" age = 45 wage = 18.75 print(type(name)) # str print(type(age)) # int print(type(wage)) # float
It’s important to be aware of the data types of your variables and to use type casting carefully to avoid errors and unexpected behavior in your code.