詳解python中lower和upper函數的使用

今天遇到一點小問題，需要編寫一個程式將List 中的無規則英文名按【首字母大寫其餘部分小寫】的方式轉換

#一開始的思路是編寫一個函數將每個名字字串【str】進行處理，如何用map進行批次處理

不得不說，大方向的思路是正確的，但在細節的處理上出了些問題

一開始我是這樣寫名字處理函數的：

[python] view plain copy
def change (name)  
    result = name[0].upper()  
    for a in name[1:len(name)]:  
        result = result + a.lower()

然後運行會報錯

[python] view plain copy
E:\PythonFile>python practice.py  
  File "practice.py", line 6  
    for a in name(1:len(name)-1) :  
                   ^  
SyntaxError: invalid syntax  
  
E:\PythonFile>python practice.py  
Traceback (most recent call last):  
  File "practice.py", line 11, in <module>  
    name_li = map (change, name_list)  
  File "practice.py", line 6, in change  
    for a in name(1,len(name)-1) :  
TypeError: &#39;str&#39; object is not callable  
  
E:\PythonFile>python practice.py  
Traceback (most recent call last):  
  File "practice.py", line 9, in <module>  
    name_li = map (change, name_list)  
  File "practice.py", line 5, in change  
    name[0] = name[0].upper()  
TypeError: &#39;str&#39; object does not support item assignment  
  
E:\PythonFile>python practice.py  
Traceback (most recent call last):  
  File "practice.py", line 10, in <module>  
    name_li = map (change, name_list)  
  File "practice.py", line 6, in change  
    name[0] = tmp  
TypeError: &#39;str&#39; object does not support item assignment  
  
E:\PythonFile>python  
Python 2.7.9 (default, Dec 10 2014, 12:24:55) [MSC v.1500 32 bit (Intel)] on win  
32  
Type "help", "copyright", "credits" or "license" for more information.  
>>> l = &#39;zxcv&#39;  
>>> print l[0]  
z  
>>> print l[0].upper  
<built-in method upper of str object at 0x02148740>  
>>> print l[0].upper()  
Z  
>>> z  
Traceback (most recent call last):  
  File "<stdin>", line 1, in <module>  
NameError: name &#39;z&#39; is not defined  
>>> ^Z  
  
  
E:\PythonFile>python practice.py  
Traceback (most recent call last):  
  File "practice.py", line 9, in <module>  
    name_li = map (change, name_list)  
  File "practice.py", line 6, in change  
    name[0] = tmp  
TypeError: &#39;str&#39; object does not support item assignment  
  
E:\PythonFile>python practice.py  
Traceback (most recent call last):  
  File "practice.py", line 13, in <module>  
    name_li = map (change, name_list)  
  File "practice.py", line 5, in change  
    tmp = chr(name[0])  
TypeError: an integer is required

試過幾次後發現大致意思是對字串的處理不能這麼做，於是查了upper（）和lower()的用法，發現這兩個函數就是直接作用在str的，所以根本不需要這麼麻煩。

修改後：

[python] view plain copy
# practice.py  
# Change the first char in every name from lower type to upper type  
  
def change (name):  
    result =  name[0:1].upper()+name[1:len(name)].lower()  
    return result  
  
name_list = ['kzd','ysy','kcw','scr','ky']  
name_li = map (change, name_list)  
print name_l

運行結果：

[python] view plain copy
E:\PythonFile>python practice.py  
['Kzd', 'Ysy', 'Kcw', 'Scr', 'Ky']

錯誤在於我企圖將字串中的元素賦值替換，這是不允許的。

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