我有一个问题，它需要一个字典并尝试找到一个字母的每个实例(如果它存在)并打印它
get_letter_frequency('all animals are equal but some animals are more equal than others')
将打印:
a appears 10 times
b appears 1 time
e appears 7 times
h appears 2 times
i appears 2 times
l appears 6 times
m appears 4 times
n appears 3 times
o appears 3 times
q appears 2 times
r appears 4 times
s appears 4 times
t appears 3 times
u appears 3 times
到目前为止，我的 get_letter_frequency 函数已经有了这个
def get_letter_frequency(a_string):
dictionary = {}
words = a_string.split()
for letters in words:
if letters != " ":
if letters in dictionary:
dictionary[letters] += 1
else:
dictionary[letters] = 1
dictionary_keys = dictionary.keys()
new_list = list(dictionary_keys)
new_list.sort()
for alphabet in new_list:
if dictionary[alphabet] == 1:
print(alphabet, "appears", dictionary[alphabet], "time")
else:
print(alphabet, "appears", dictionary[alphabet], "times")
但这反而给了我字典中的所有字母，并告诉我它出现了多少次。
all appears 1 time
animals appears 2 times
are appears 2 times
but appears 1 time
equal appears 2 times
more appears 1 time
others appears 1 time
some appears 1 time
than appears 1 time
你能帮忙吗？谢谢。
请您参考如下方法:
错误在这些行中:
words = a_string.split()
for letters in words:
您期望它遍历 words 中的所有字母，但它实际上遍历了单个单词。在 Python 中，您可以将字符串当作字符的 list 来使用，因此将 `for 行更改为以下行将起作用:
for letters in a_string:
