In Python, the integer type (abbreviated as int) is also called integer, which consists of positive integers, 0 and negative integers, excluding decimals and fractions. In Python, there is no limit to the length of integers, but it is limited by available memory. Floating-point numbers are also called decimals, which correspond to real numbers mathematically. In Python, floating-point numbers are numbers with decimal points. Because the number of floating-point numbers stored in computer memory is limited, it will end approximately after exceeding the specified length. So floating-point numbers are not necessarily exact values. Complex number consists of real part and imaginary part, which extends real number to imaginary number, and its mathematical expression is a+bj(a and B are both real numbers). A is called the real part, b is called the imaginary part, j(J) is the imaginary unit (j_=- 1), and bj is called the imaginary number.