iteration, list, dictionary, file iteration

for i in k :i=k_iter_()

# f=open('dog.txt','r',encoding='utf8')#If the file does not exist, you can create a new file 
# f.seek('Hello',1)#Search through the seek cursor 
# print(f .tell()) #Iteration 
: the for loop follows the iterator, it can only go forward but not backward, 
# k=[1,2,3] 
# for i in k:#i=k._iter_() 
#      print( i) 
# k = [1, 2, 3, 4] 


# # print(k[0]) 
# index = 0 
# while index < len(k): 
#      print(k[index]) 
#      index += 1 
# dic={'a':2,'b':7}#Dictionary iteration 
# res=dic.__iter__() 
# print(res.__next__()) 
f=open( ' eze.py ',' r+ ' ) 
#File iteration operation # for i in f 
res=f. __iter__ ()
 print (res. __next__ (),end= ' 2 ' )


k = [1, 2, 3, 4] #List iteration # iter_1=k.__iter__() 
# Follow the iterator protocol to produce iterable objects 
# print(iter_1.__next__())#Get the value of the object list 
# print(iter_1 .__next__())#Get the value of the object list