Mastering Python conditionals and loops is a key programming skill

Essential programming skills: Master conditional statements and loop statements in Python

In today's information age, programming has become an increasingly important skill. Whether in fields such as scientific research, data analysis, software development, or artificial intelligence, programming plays a vital role. Among many programming languages, Python is increasingly popular among developers for its simplicity, ease of learning, and powerful functions. In Python, conditional statements and loop statements are indispensable basic tools when writing programs. This article will introduce these two techniques in detail and give code examples.

1. Conditional Statements

Conditional statements are used in programs to selectively execute different code blocks based on different conditions. The most classic conditional statement is the if statement. In Python, the syntax of the if statement is as follows:

if 条件:
    # 如果条件为真，执行这里的代码块
else:
    # 如果条件为假，执行这里的代码块

Among them, the condition can be any expression that returns a Boolean value, such as comparison, logical and member operations, etc. The following is a simple example to determine whether a number is positive and output the corresponding information:

num = 10

if num > 0:
    print("这个数是正数")
else:
    print("这个数不是正数")

2. Loop statement

The loop statement is used to repeatedly execute a piece of code so that the program can Save time and reduce redundant code by performing an operation over and over again. In Python, the most commonly used loop statements are for loops and while loops.

1. for loop

The for loop is used to traverse the elements in an iterable object, such as a list, string, or dictionary. Its syntax is as follows:

for 变量 in 可迭代对象:
    # 执行循环体中的代码块

The following is an example to calculate the sum of 1 to 10:

sum = 0

for i in range(1, 11):
    sum += i

print("1到10的和为：%d" % sum)

2. while loop

while loop is used to calculate the sum according to Code is repeatedly executed under a certain condition, and the loop is terminated only when the condition is not met. Its syntax is as follows:

while 条件:
    # 执行循环体中的代码块

The following is an example, outputting the square of 1 to 10:

n = 1

while n <= 10:
    square = n * n
    print("%d的平方：%d" % (n, square))
    n += 1

3. Comprehensive example

Next, let’s look at a comprehensive example , implement a number guessing game through conditional statements and loop statements. The rules of the game are to randomly generate an integer from 1 to 100, and players guess this random number by entering the guessed number until they guess correctly. The game sample code is as follows:

import random

number = random.randint(1, 100)
guess = 0

while guess != number:
    guess = int(input("请输入您猜测的数字："))

    if guess < number:
        print("猜小了，请继续猜测！")
    elif guess > number:
        print("猜大了，请继续猜测！")
    else:
        print("恭喜您，猜对了！")

The above sample code shows how to use conditional statements and loop statements to implement a simple guessing number game. In actual applications, it can be expanded and improved accordingly according to needs.

Summary:

Mastering conditional statements and loop statements in Python is the basis of programming and the key to improving programming efficiency and flexibility. Through conditional statements, we can selectively execute code blocks based on different conditions; through loop statements, we can repeatedly execute a certain piece of code, thereby reducing duplication of work. I hope this article will help you understand and master conditional statements and loop statements in Python, and further improve your programming skills. Enjoy programming!

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