for循环主要用于循环取值
student=【'summer','dream','cold'】
i=0
while i <len(students):
print (student[1])
i+=1
for item in student:
print(item)
for item in 'hello'
print(item)
dic={'x','444','y','333','z','555'}
for k in dic:
print(k,dic[k])
for i in range(1,10,3):
print(i)
for i in range(10):
print(i)
student=['summer','dream','cold']
for item in student:
print(item)
for i in range(len(student)):
print(i,student[i])