Python-如何修改文本文件？

取决于你要做什么。要附加，可以用

"a"

 with open("foo.txt", "a") as f:     f.write("new linen")

如果要先添加某些内容，则必须先从文件中读取：

with open("foo.txt", "r+") as f:     old = f.read() # read everything in the file     f.seek(0) # rewind     f.write("new linen" + old) # write the new line before