Question

编写一个函数analyze_text，它接收一个字符串作为输入。该函数应计算文本中字母字符（a到z或A到Z）的数量，并跟踪字母“e”（大写或小写）的数量。

该函数应返回文本分析，如下所示：

该文本包含240个字母字符，其中105个（43.75％）为“e”。

我需要使用isalpha函数，可以像这样使用：

"a".isalpha() # => evaluates to True
"3".isalpha() # => evaluates to False
"&".isalpha() # => False
" ".isalpha() # => False

mystr = "Q"
mystr.isalpha() # => True

该功能应通过以下测试：

from test import testEqual

text1 = "Eeeee"
answer1 = "The text contains 5 alphabetic characters, of which 5 
(100.0%) are 'e'."

testEqual(analyze_text(text1), answer1)

text2 = "Blueberries are tasteee!"
answer2 = "The text contains 21 alphabetic characters, of which 7
(33.3333333333%) are 'e'."

testEqual(analyze_text(text2), answer2)

text3 = "Wright's book, Gadsby, contains a total of 0 of that most
common symbol ;)"

answer3 = "The text contains 55 alphabetic characters, of which 0
(0.0%) are 'e'."

testEqual(analyze_text(text3), answer3)

所以我试过了：

def analyze_text(text):

    text = input("Enter some text")
    alphaChars = len(text)

#count the number of times "e" appears
    eChars = text.count('e')

#find percentage that "e" appears
    eCharsPercent = eChars / alphaChars

    print("The text contains" + alphaChars + "alphabetic characters, of 
    which" + eChars + "(" + eCharsPercent + ") are 'e'.")

from test import testEqual

text1 = "Eeeee"
answer1 = "The text contains 5 alphabetic characters, of which 5
(100.0%) are 'e'."

testEqual(analyze_text(text1), answer1)

text2 = "Blueberries are tasteee!"
answer2 = "The text contains 21 alphabetic characters, of which 7
(33.3333333333%) are 'e'."

testEqual(analyze_text(text2), answer2)

text3 = "Wright's book, Gadsby, contains a total of 0 of that most
common symbol ;)"
answer3 = "The text contains 55 alphabetic characters, of which 0
(0.0%) are 'e'."

testEqual(analyze_text(text3), answer3)

正如您所看到的，我尝试的不使用isalpha功能（我不知道如何/在何处使用它）。此外，无论测试是否通过，该函数都不会返回。 Visualize python不支持“test”，我在书中使用的文本编辑器说我有缩进错误（？）我不知道从哪里开始 - 请帮忙。

Screenshot of Book Text Editor

编辑：现在收到“TypeError：无法连接第12行的'str'和'int'对象”（以“print”开头的行）。

Answer 1

这是一个通过测试的analyse_text函数：

def analyze_text(text):
    filtered = [c.lower() for c in text if c.isalpha()]
    cnt = filtered.count('e')
    result = "The text contains {} alphabetic characters, of which {} ({}%) are 'e'.".format(len(filtered),cnt,str(100.0*cnt/len(filtered))[:13])
    return result

创建一个包含小写字母的所有字母数字列表，使用一个很好的列表理解（这是你缺少的部分），创建filtered变量
计数字母e（你说得对），创建cnt计数器
格式字符串符号（使用一点点黑客来获得33.3333333权利，也许可以做得更好一些）。获取确切的字符串有点无意义......，创建在{/ li>之后返回行的result字符串

Python函数计算字母数字的数量，跟踪“e”出现的次数

1 个答案: