ValueError: must have exactly one of create/read/write/append mode

ValueError: must have exactly one of create/read/write/append mode

 

fo = open('runoob.txt', 'rw+')

python 中文件打开操作的mode中没有“rw”

合法的mode有：

r、rb、r+、rb+、w、wb、w+、wb+、a、ab、a+、ab+