从python中的字符串中提取单个字母

Question

是否有可能从程序的用户在python中定义的字符串中提取单个字母？比如我想提取该字符串的单个字母：

 x = raw_input("Letters i want to extract") 

Answer 1

您可以使用一个for循环这样

x = raw_input("Letters i want to extract") 
for ch in x: 
    print x 

您还可以得到单个字符这样

x[0] # first character 
x[1] # second character 

你可以转换成像这样的列表

char_list = list(x) 

Answer 2

>>> s = 'test' 
>>> s[0] 
't' 
>>> list(s) 
['t', 'e', 's', 't'] 
>>> for ch in s: 
...  print ch 
... 
t 
e 
s 
t 

Answer 3

X =的raw_input（ “信我想提取”）

for i in x: 
    print i 
    #or do whatever you please 

我觉得这是你在找什么。代码片段 - 它遍历字符串并输出每个字母。而不是印刷，你可以做你想做的事。

您还可以通过语法x [index_value]访问每个字母的个性。

即。

x[0] would yield 'L' 
x[1] would yield 'e' 

Answer 4

变量有一个名称和一个值。

字典是与值相关联的名称的集合。因此，出于您的目的，您可能可以创建一本字典并将其视为“一组变量”。

例如，如果你想要的“单变量” x中每个字母是柜台，那么你可以使用此代码：

def stats(): 
    x = raw_input("Letters i want to extract: ") 
    data = raw_input("Text I want to do some stats on: ") 

    # make a dictionary of letters in x 
    d = {} 
    for chr in x: 
     d[chr] = 0 # initialize counter 

    # collect stats 
    for item in data: 
     if item in d: 
     d[item] += 1 

    # show results in a couple of ways 
    print "The full tally: %r" % d 
    for chr in x: 
     print "There were %d occurrences of %c in the text" % (d[chr], chr) 

下面是一个例子运行。

>>> stats() 
Letters i want to extract: bell 
Text I want to do some stats on: hello world 
The full tally: {'b': 0, 'e': 1, 'l': 3} 
There were 0 occurrences of b in the text 
There were 1 occurrences of e in the text 
There were 3 occurrences of l in the text 
There were 3 occurrences of l in the text 

Answer 5

字符串是Python中的一个序列，索引从零开始。为了得到一个特定的元素或字符串（字符）只使用以下内容：

>>> x = "This is a string" 
>>> first_letter = x[0] 
>>> second_letter = x[1] 
>>> last_letter = x[-1] 
>>> print first_letter 
T 
>>> print last_letter 
g 
>>> 

你也可以遍历它很容易，像这样：

>>> for index, letter in enumerate(x): 
    print index, letter 

0 T 
1 h 
2 i 
3 s 
4 
5 i 
6 s 
7 
8 a 
9 
10 s 
11 t 
12 r 
13 i 
14 n 
15 g 
>>>