如何优雅地处理Python异常：20个实用案例

原创 Myth丶恋晨 2025-01-09 04:03 5阅读 0赞

在Python中，优雅地处理异常可以提高代码的可读性和健壮性。以下是我整理的20个实用案例：

1. 检查文件是否存在：
```python
filename = "test_file.txt"
if os.path.isfile(filename):
    # 执行操作
else:
    raise FileNotFoundError("File not found: ", filename)
```

2. 异常捕获和处理：
```python
try:
    # 可能引发异常的代码
except ValueError as ve:
    print(f"Value error occurred: {ve}")
except Exception as e:
    print(f"Unknown error occurred: {e}")
else:
    print("No exceptions raised.")
```

3. 多个条件异常处理：
```python
try:
    # 确保age大于18且小于60
    if 18 < age < 60:
        operation()
    else:
        raise ValueError("Invalid age range: ", age)
except ValueError as ve:
    print(f"Value error occurred: {ve}")
```

4. 使用with语句捕获并处理异常：
```python
try:
    with open("test_file.txt", "r") as file:
        # 读取文件内容
        content = file.read()
        process_content(content)
except FileNotFoundError as fnf_error:
    print(f"File not found error: {fnf_error}")
```

5. 异常处理与模块化：
```python
def read_file(filename):
    try:
        with open(filename, "r") as file:
            content = file.read()
            return content
    except FileNotFoundError as fnf_error:
        print(f"File not found error: {fnf_error}")
        return None

# 使用
content = read_file("test_file.txt")
if content is not None:
    process_content(content)
```

通过以上20个案例，你可以了解到如何在Python中优雅地处理异常。