题目说明

f=open('/data/        ①        ','r')
text=f.read()
lst=[]
s=""
def judge(        ②        ):
    if st in lst:
        return False
    else:
        return True
for i in range(len(text)):
    c=        ③
    if"a"<=c<="z" or"A"<=c<="Z":
        s=s+c
    else:
        if judge(s):
            lst.append(s)
        s=""
print("出现的不同单词个数为:",len(lst))