在 Python 中，循环语句是实现重复操作的重要工具。本文将深入探讨 Python 循环语句的高级应用。
for 循环的高级用法
# 遍历字典并同时获取键和值
my_dict = {'a': 1, 'b': 2, 'c': 3}
for key, value in my_dict.items():
print(f'Key: {key}, Value: {value}')
# 遍历多个序列
names = ['Alice', 'Bob', 'Charlie']
ages = [25, 30, 35]
for name, age in zip(names, ages):
print(f'{name} is {age} years old.')
while 循环的高级技巧
# 使用条件判断和计数器控制循环
counter = 0
while counter < 5:
print(counter)
counter += 1
# 处理循环中的异常
while True:
try:
num = int(input("Enter a number: "))
break
except ValueError:
print("Invalid input. Please enter a number.")
循环中的嵌套与控制
# 嵌套循环实现矩阵乘法
matrix1 = [[1, 2], [3, 4]]
matrix2 = [[5, 6], [7, 8]]
result = [[0, 0], [0, 0]]
for i in range(len(matrix1)):
for j in range(len(matrix2[0])):
for k in range(len(matrix2)):
result[i][j] += matrix1[i][k] * matrix2[k][j]
for row in result:
print(row)
循环的优化与性能提升
# 使用列表推导式替代简单的循环
numbers = [1, 2, 3, 4, 5]
squared_numbers = [num ** 2 for num in numbers]
print(squared_numbers)
# 在循环中避免不必要的计算
data = [10, 20, 30, 40, 50]
total = 0
min_value = min(data)
for num in data:
if num > min_value:
total += num
print(total)
