Python Interactive Guide - Step 1: Basic Syntax and Data Types (2) - int, float

This is a continuation of “Step 1: Basic Syntax and Data Types”.

1.3. Basic Data Types

1.3.1. What is a Type?

• Python allows you to work with various kinds of data, such as strings and numbers. These different kinds of data are called types.
• You can use the type() function to check the type of data.
  • Functions are, simply put, mechanisms that take input data, process it, and return output results. We’ll cover them in more detail later.

• From the execution result, we can see that the string "Hello!" is of type str and the number 100 is of type int.

1.3.2. Numbers (int Type, float Type)

• In Python, there are two basic numeric types: integers (int) and floating-point numbers (float).

Basic Numeric Operations

• You can perform addition (+), subtraction (-), multiplication (*), and division (/) operations with numbers.
• You can also use the print function to display numeric values on the screen.

• You can also calculate the quotient (//) and remainder (%) in division.

• You can also perform exponentiation (**) calculations.

Type Conversion

• You can use the int function to convert a decimal to an integer (removing the decimal portion).
• You can use the float function to convert an integer to a decimal.

Maximum and Minimum Values for int Type

• The int type has no upper or lower limit.
  • You can work with numbers of any size as long as memory allows.

Scientific Notation

• With float type, you can use scientific notation.
  • For example, $3.14 \times 10^{5}$ can be written as 3.14e5.

Maximum and Minimum Values for float Type

• The float type has upper and lower limits.

• In float type, values exceeding the upper (lower) limit become inf (-inf).

• In some operations, an OverflowError occurs if the calculation result exceeds the upper (lower) limit.

Float Type Precision

• The float type also has limitations in precision.

• Special care is needed for float calculations.

This type of error is called a “rounding error” and occurs because decimal numbers are represented internally in binary. For calculations requiring high precision, Python provides the Decimal data type.