如何使用python计算没有空格的字符串中的字符？

Question

我创建了一个函数来计算字符串中的字符数，但它也会计算空格。

这是我的代码：

def count_characters_in_string(mystring):
    string_1 = mystring
    print("The number of characters in this string is:", len(string_1))
count_characters_in_string("Apples and Bananas")

有没有办法不计算空格？

Answer 1

这个不会使用sum 、 str.isspace以及issubclass(bool, int)的事实在内存中创建虚假list或str ：

def count_characters_in_string(mystring):
    return sum(not c.isspace() for c in mystring)

Answer 2

您可以split字符串（不指定分隔符意味着根据任何空格拆分），然后总结结果字符串的长度

def count_characters_in_string(string):
    return sum([len(word) for word in string.split()])

print("The number of characters in this string is:", count_characters_in_string("Apples and Bananas"))

编辑：按照@schwobaseggl 的有用建议，我创建了 3 个版本的函数并定时它们以找出map选项实际上是最快的

def count_characters_in_string(string):
    return sum([len(word) for word in string.split()])

def count_characters_in_string_gen(string):
    return sum(len(word) for word in string.split())

def count_characters_in_string_map(string):
    return sum(map(len, string.split()))


%timeit count_characters_in_string("Apples and Bananas")
718 ns ± 21.8 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit count_characters_in_string_gen("Apples and Bananas")
812 ns ± 13.6 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit count_characters_in_string_map("Apples and Bananas")
607 ns ± 19.9 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

Answer 3

用这个：

def count_characters_in_string(input_string):

    letter_count = 0

    for char in input_string:
        if char.isalpha():
            letter_count += 1

    print("The number of characters in this string is:", letter_count)

这也有效：

def count_characters_in_string(input_string):

    letter_count = len(input_string.replace(" ",""))

    print("The number of characters in this string is:", letter_count)

当你然后运行：

count_characters_in_string("Apple Banana")

它会输出：

"The number of characters in this string is: 11"

Answer 4

好吧，您可以做一件简单的事情，使用相同的字符串创建一个新变量，将该字符串上的所有空白替换为空，然后您获得两个字符串的长度并获得差异。

string1 = "asd asd asd asd asd"
string2 = string1
string2.replace(" ", "")
size1 = len(string1)
size2 = len(strgin2)
size3 = size1 - size2

干杯

Answer 5

您如何看待list comprehension len ？

def count_characters_in_string(mystring):
    return len([character for character in mystring if character.isalpha()])

Answer 6

解决方案之一可能是遍历字符并检查它是否不是空格，然后按如下方式递增计数：

def count_characters_in_string(mystring):
    count = 0
    for x in mystring:
        if x !=' ':
            count+=1
    return count

res = count_characters_in_string("Apples and Bananas")
print(res)