Python文件读写open函数详解_python_

filename = 'test.txt' # 以只读方式打开test.txt文件 fd = open(filename, 'r', encoding='utf-8') # fd.read(self, n) 按指定的长度读取文件内容,为空则读取全部内容 lines = fd.read() print(lines) fd.close() print('------------------read------------------------') # 以写入模式打开test.txt文件 fd = open(filename, 'w', encoding='utf-8') # fd.write(self, str) 将str写入文件 lines_w = fd.write('java\nPython\tGolang') print(lines_w) fd.close() print('------------------write------------------------') # 以追加模式打开文件 fd = open(filename, 'a', encoding='utf-8') lines_a = fd.write('java\nPython\tGolang') print(lines_a) fd.close() print('------------------append------------------------') # 以读写模式打开文件(r+) fd = open(filename, 'r+', encoding='utf-8') print(fd.read()) lines_str = fd.write('java\nPython\tGolang') print(fd.read()) fd.close() print('------------------readWrite------------------------') # 以读写模式打开文件(w+) fd = open(filename, 'w+', encoding='utf-8') lines_str = fd.write('java\nPython\tGolang') print(fd.read()) # 文件打开时清空文件内容，虽然写入了文件，但未保存，因此读取文件为空 fd.close() print('------------------readWrite------------------------') # 以读写模式打开文件(a+) fd = open(filename, 'a+', encoding='utf-8') print(fd.read()) # 按行读取 print(fd.readlines(2)) lines_str = fd.write('java\nPython\tGolang') print(fd.read()) fd.close() print('------------------readWrite------------------------')