Python经典程序100例，从基础到进阶练习项目
Python经典程序100例
1. 第一个Python程序：打印“Hello, World!”
python
print("Hello, World!")
2. 变量交换
python
a = 6
b = 7
使用临时变量
temp = a
a = b
b = temp
print(f"a: {a}, b: {b}")
不使用临时变量
a, b = b, a
print(f"a: {a}, b: {b}")
3. 判断奇偶性
python
num = int(input("请输入一个整数: "))
if num % 2 == 0:
print(f"{num} 是偶数")
else:
print(f"{num} 是奇数")
4. 计算阶乘
python
def factorial(n):
if n == 0:
return 1
else:
return n factorial(n-1)
num = int(input("请输入一个整数: "))
print(f"{num} 的阶乘是 {factorial(num)}")
5. 斐波那契数列
python
def fibonacci(n):
if n <= 1:
return n
else:
return fibonacci(n-1) + fibonacci(n-2)
num = int(input("请输入一个整数: "))
print(f"第 {num} 个斐波那契数是 {fibonacci(num)}")
6. 冒泡排序
python
def bubble_sort(lst):
n = len(lst)
for i in range(n):
for j in range(0, n-i-1):
if lst[j] > lst[j+1]:
lst[j], lst[j+1] = lst[j+1], lst[j]
return lst
numbers = [64, 34, 25, 12, 22, 11, 90]
print("排序前:", numbers)
numbers = bubble_sort(numbers)
print("排序后:", numbers)
7. 选择排序
python
def selection_sort(lst):
for i in range(len(lst)):
min_idx = i
for j in range(i+1, len(lst)):
if lst[j] < lst[min_idx]:
min_idx = j
lst[i], lst[min_idx] = lst[min_idx], lst[i]
return lst
numbers = [64, 34, 25, 12, 22, 11, 90]
print("排序前:", numbers)
numbers = selection_sort(numbers)
print("排序后:", numbers)
8. 插入排序
python
def insertion_sort(lst):
for i in range(1, len(lst)):
key = lst[i]
j = i-1
while j >=0 and key < lst[j] :
lst[j+1] = lst[j]
j -= 1
lst[j+1] = key
return lst
numbers = [64, 34, 25, 12, 22, 11, 90]
print("排序前:", numbers)
numbers = insertion_sort(numbers)
print("排序后:", numbers)
9. 反转字符串
python
def reverse_string(s):
return s[::-1]
s = "Hello, World!"
print(f"反转后的字符串是: {reverse_string(s)}")
10. 字符串替换
python
s = "Hello, World!"
s = s.replace("World", "Python")
print(s)
这只是Python经典程序100例中的一部分，后续将涉及更复杂的算法、数据结构、文件操作、网络编程、GUI编程等。每个例子都旨在帮助读者理解和掌握Python的某个特定方面。通过这100个例子，读者可以从基础到进阶，逐步提高Python编程能力。
