Python中的枚举函数enumerate()的具体用法

ls = ['a', 'b', 'c']
# method 1
for i in range(len(ls)):
    print(i， end=' ')
    print(ls[i])
 
# method 2
for s in ls:
    print(ls.index(s), end=' ')
    print(s)
 
# method 3
for i, s in enumerate(ls):
    print(i, end=' ')
    print(s)

>>> lst = [1,2,3,4,5,6]
>>> for index,value in enumerate(lst):
  print ('%s,%s' % (index,value))
  
0,1
1,2
2,3
3,4
4,5
5,6

#指定索引从1开始
>>> lst = [1,2,3,4,5,6]
>>> for index,value in enumerate(lst,1):
print ('%s,%s' % (index,value))

1,1
2,2
3,3
4,4
5,5
6,6

#指定索引从3开始
>>> for index,value in enumerate(lst,3):
print ('%s,%s' % (index,value))

3,1
4,2
5,3
6,4
7,5
8,6

count = len(open(filepath, 'r').readlines())

count = 0
for index, line in enumerate(open(filepath,'r'))： 
   count += 1