python - 删除字符串的每隔一个字符(必须是字母或数字)而不影响 python 中的空格

Question

例如，如果我的初始字符串是 "hello world! how are you? 0" 我希望结果字符串是 "hlo ol! hw r yu?"。到目前为止，我有以下代码:

s = "hello world! how are you? 0"  
for char in s:
    if char.isalpha() == True:

Answer 1

i = 0
s2 = ""
for char in s:
    if char.isalpha() or char.isnumeric():
        if (i % 2) == 0:
            s2 += char
        i += 1 
    else:
        s2 += char

输出字符串 s2 将是:

# s2 = 'hlo ol! hw r yu? '