Python 无限值 - Introduction for Programmers

In Python, we have the facility to represent infinite values using the keyword inf. The inf represents the mathematical concept of infinity. In this article, we will learn how to use infinite values in Python and how they can be helpful for programmers.

Using Infinite Values in Python

In Python, inf is used to denote positive infinity, while -inf is used to represent negative infinity. These values can be used for mathematical computations wherever infinity is needed:

x = float('inf')
print(x)   # Output: inf

y = float('-inf')
print(y)   # Output: -inf

We can perform arithmetic operations with inf and -inf as well:

print(1000 * float('inf'))        # Output: inf
print(-2500 * float('-inf'))     # Output: inf
print(0 / float('-inf'))         # Output: -0.0

Application of Infinite Values in Programming

Infinite values can be helpful in a number of programming scenarios. One such example is when we want to set an initial value for a variable, but we don't know what the maximum limit is. In such cases, we can set the variable to inf:

age = float('inf')   # initial value
while age > 30:      # loop until the age is less than or equal to 30
  age = int(input("Enter your age: "))

In the above example, the age variable is set to inf initially. The while loop will continue until we receive an input which sets the value of age to 30 or less.

Another application of infinite values is in sorting algorithms. When we sort a list of numbers, elements with inf values will always appear at the end of the sorted list. This can be helpful in some situations where we want certain elements to appear last in the sorted list.

In conclusion, Python's ability to represent infinite values as inf and -inf can be helpful in a variety of situations. As a programmer, it is important to be familiar with these concepts and the ways they can be utilized in programming.