Python：遍历字符串和列表

Posted 2021-02-26

## The first example uses a string as the sequence to create a list of characters in the string:
 
>>>word = "Python"
>>>list = []
>>>for ch in word:
>>>    list.append(ch)
>>>print list
['P', 'y', 't', 'h', 'o', 'n']
 
 
## This example uses the range() function to create a temporary sequence of integers the size of a list so the items in the list can be added to a string in order:
 
>>>string = ""
>>>for i in range(len(list)):
>>>    string += list[i]
>>>print string
Python
 
 
 
## This example uses the enumerate(string) function to create a temporary sequence. The enumerate function returns the enumeration in the form of (0, s[0]), (1, s[1]), and so on, until the end of the sequence string, so the for loop can assign both the i and ch value for each iteration to create a dictionary:
 
>>>dict = {}
>>>for i,ch in enumerate(string):
>>>    dict[i] = ch
>>>print dict
{0: 'P', 1: 'y', 2: 't', 3: 'h', 4: 'o', 5: 'n'}
 
 
 
## This example uses a dictionary as the sequence to display the dictionary contents:
 
>>>for key in dict:
>>>    print key, '=', dict[key]
0 = P
1 = y
2 = t
3 = h
4 = o
5 = n