python文件读写案例

在Python中，文件读写操作是非常常见的任务。以下是几个基本的案例：

**打开文件进行读取（read模式）**:

# 打开文件（默认文本模式）
with open('example.txt', 'r') as file:
    # 读取整个文件内容
    content = file.read()
    print(content)

**逐行读取（lines模式）**:

with open('example.txt', 'r') as file:
    for line in file:
        print(line.strip())  # 去除行尾的换行符

**写入文件（write模式）**:

content = 'Hello, World!'
with open('output.txt', 'w') as file:
    file.write(content)

**追加内容到文件（append模式）**:

with open('output.txt', 'a') as file:
    file.write('\nThis is a new line.')

**处理异常**:

try:
    with open('non_existent_file.txt', 'r') as file:
        content = file.read()
except FileNotFoundError:
    print("File not found.")