[已解决]python新人提问，请问该如何展开下面的代码？

if all (each in str1 for each in grade):

str1 = 'ABCDF '
grade = input('请输入评分等级：')

if all (each in str1 for each in grade):
      temp = True
else:
      temp = False
print(temp)

def all(iterable):
    for element in iterable:
        if not element:
            return False
    return True

str1 = 'ABCDF '
grade = input('请输入评分等级：')

for i in grade:
    if i in str1:
         temp = True 
    else:
        temp = False
print(temp)

for each in grade:
    if each in str1:
        print(True)

str1 = 'ABCDF '
grade = input('请输入评分等级：')
temp = True
for i in grade:
    if i in str1:
         continue 
    else:
        temp = False
print(temp)