Question

我写了这个函数：

def make_upper(words):
    for word in words:
        ind = words.index(word)
        words[ind] = word.upper()

但是我需要使用不熟悉的lambda函数来编写它。有什么想法吗？

我还写了一个函数来计算每个字母出现的频率：

def letter_cnt(word,freq):
    for let in word:
        if let == 'A': freq[0]+=1
        elif let == 'B': freq[1]+=1
        elif let == 'C': freq[2]+=1
        elif let == 'D': freq[3]+=1
        elif let == 'E': freq[4]+=1

所以我需要用字典来编写它。有什么建议吗？

Answer 1

Python 2.7.12 (default, Nov 19 2016, 06:48:10) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> words = ['werfwr', 'fwerw', 'ghebe', 'wgergwtg', 'gbeyteb']
>>> def make_upper(words):
...     return map(lambda word: word.upper(), words)
... 
>>> make_upper(words)
['WERFWR', 'FWERW', 'GHEBE', 'WGERGWTG', 'GBEYTEB']
>>> def letter_cnt(word):
...     letters = {}
...     for symbol in word:
...         symbol = symbol.lower()
...         if 'a' <= symbol and symbol <= 'z':
...             if symbol in letters:
...                 letters[symbol] += 1
...             else:
...                 letters[symbol] = 1
...     return letters
... 
>>> letter_cnt('werfervt')
{'e': 2, 'f': 1, 'r': 2, 't': 1, 'w': 1, 'v': 1}

使用lambda函数和字典来显示函数可以用不同的方式编写

1 个答案: