Question

在给定的字典中，每个键都是一个小写字母，每个值都是以该字母开头的小写字母数。 str参数是一个小写字母。根据字典中的值，返回以该字母开头的单词的百分比。

注意：使用浮点除法。

def get_letter_percentage(dictionary, s):
   '''(dict of {str : int}, str) -> float'''

# Start with a counter for the sum of the values.
count = 0
# And then look at the key and value of the dictionary
for (key, value) in dictionary.items():

这是我被卡住的地方。我知道我需要创建一个值的总和，以便进行浮点除法。

# guessing it is something along these lines
count = len(values) #??

Answer 1

也许你可以在你的功能中尝试这样的事情：

dictionary = {'a': 5, 'b': 8, 'c':15}
sum = 0
for (key, value) in dictionary.items(): sum += value
percentage = dictionary['a'] / (sum + 0.0)
print "percentage of '%s' is %.2f %%" % ('a' , percentage*100)

Answer 2

def get_letter_percentage(dictionary, s):
   '''(dict of {str : int}, str) -> float'''

   return dictionary[s] * 1.0 / sum(dictionary.values())

百分比是出现次数除以总出现次数。注意乘以1.0以避免int除。

Answer 3

如果每个值都是每个字母的单词数，那么找到总和的代码将是：

sum = 0
for (key, value) in dictionary:
    sum = sum + value

然后是一个案例：

def get_letter_percentage(dictionary, letter):
    return dictionary[letter] / sum

Answer 4

我想出了这个：

mydict = {"a":5, "b":1, "c":4, "d":3, "e":6}


def get_letter_percentage(dictionary, s):
    sum = 0
    for key in dictionary:
        sum += dictionary[key]

    return float(dictionary[s]) / float(sum)

print get_letter_percentage(mydict, "b")

Answer 5

def get_letter_percentage(stats, letter):
  return stats[letter] / (sum(stats.values()) + 0.0)

获取python字典中字母的百分比

5 个答案: