python - 如何检查字母(值)是否在字典中？

Question

希望你一切顺利。我正在研究字典程序:

strEntry = str(input("Enter a string: ").upper())
strEntry = strEntry.replace(",", "")
strEntry = strEntry.replace(" ", "")

print('')

def freq_finder(strFinder):
  dict = {}
  for i in strFinder:
    keys = dict.keys()
    if i in keys:
      dict[i] += 1
    else:
      dict[i] = 1
  return dict

newDic = freq_finder(strEntry)

print(newDic)

newLetter = str(input("Choose a letter: ").upper())

if newLetter in newDic.values():
  print("Number of occurrence of", message.count(newLetter))
  newDic.pop(newLetter)
  print("Dictinary after that letter removed:", newDic)
else:
  print("Letter not in dictionary")

sortedDic = sorted(newDic)
print(sortedDic)

在这部分之前一切正常:

newLetter = str(input("Choose a letter: ").upper())

if newLetter in newDic.values():
  print("Number of occurrence of", message.count(newLetter))
  newDic.pop(newLetter)
  print("Dictinary after that letter removed:", newDic)
else:
  print("Letter not in dictionary")

我想弄清楚如何检查字母是否在字典中。如果不是，则显示消息“Letter not in dictionary”。否则，显示该字母的频率计数，从字典中删除该字母，并在删除该字母后显示字典。

它应该看起来像这样:

Enter a string: Magee, Mississippi

Dictionary:  {'M': 2, 'A': 1, 'G': 1, 'E': 2, 'I': 4, 'S': 4, 'P': 2}
Choose a letter: s
Frequency count of that letter: 4
Dictionary after that letter removed:  {'M': 2, 'A': 1, 'G': 1, 'E': 2, 'I': 4, 'P': 2}
Letters sorted: ['A', 'E', 'G', 'I', 'M', 'P']

如果您能告诉我哪里出了问题以及如何解决，我将不胜感激。

Answer 1

检查键，而不是值(因为值是数字，而不是字母)-

if newLetter in newDic:  # Or if newLetter in list(newDic.keys())
  print("Number of occurrence of", message.count(newLetter))

为此 - 字典:{'M': 2, 'A': 1, 'G': 1, 'E': 2, 'I': 4, 'S': 4, 'P ': 2}，你可以使用 Collections.Counter相反