在每次出现“空白”后替换字符串中的前几个字符

def replace_after_blank(string, num_chars, replacement):
    # 寻找空白字符的位置
    index = string.find(" ")
    while index != -1:
        # 获取空白字符后的前几个字符
        substring = string[index+1:index+1+num_chars]
        # 替换前几个字符
        string = string.replace(substring, replacement, 1)
        # 继续寻找下一个空白字符的位置
        index = string.find(" ", index+1)
    return string

# 示例用法
original_string = "在每次出现“空白”后替换字符串中的前几个字符"
num_chars_to_replace = 3
replacement_string = "替换后"
result = replace_after_blank(original_string, num_chars_to_replace, replacement_string)
print(result)