在 Python 中根据动态字符串提取标题和定义

一位用户想从一个动态字符串中提取标题和定义，其中标题和定义之间用空格分隔，而标题和定义的长度是未知的。他们希望找到一种方法来提取标题和定义，而不使用 string.split() 方法。

解决方案

有几种方法可以从动态字符串中提取标题和定义，具体取决于字符串的格式和想要实现的效果。

方法一：使用 split() 方法

my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
verb, title, definition = my_string.split(' ', 2)
print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

这种方法简单易用，但需要注意它只适用于标题和定义之间只有一个空格的情况。如果标题和定义之间有多个空格，则需要使用 None 作为分隔符来分割字符串。

my_string = "!save    python  Python is a high-level object oriented language created by Guido van Rossum."
verb, title, definition = my_string.split(None, 2)
print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

方法二：使用正则表达式

import re

my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
m = re.match('(/S+)/s*(/S+)/s*(.*)')
verb = m.group(1)
title = m.group(2)
definition = m.group(3)

print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

这种方法可以处理标题和定义之间有多个空格的情况，但对于新手来说可能有点复杂。

方法三：使用自定义函数

def extract_title_and_definition(my_string):
    """Extract the title and definition from a given string.

    Args:
        my_string: The string to extract the title and definition from.

    Returns:
        A tuple containing the title and definition.
    """

    # Find the first space character.
    space_index = my_string.find(' ')

    # Extract the verb.
    verb = my_string[:space_index]

    # Extract the title.
    start_index = space_index + 1
    end_index = my_string.find(' ', start_index)
    title = my_string[start_index:end_index]

    # Extract the definition.
    start_index = end_index + 1
    definition = my_string[start_index:]

    return verb, title, definition


my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
verb, title, definition = extract_title_and_definition(my_string)

print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

这种方法比较灵活，可以适应各种格式的字符串，但需要编写自定义函数来提取标题和定义。

代码例子

以下是使用 split() 方法提取标题和定义的代码示例：

my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
verb, title, definition = my_string.split(' ', 2)
print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

以下是使用正则表达式提取标题和定义的代码示例：

import re

my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
m = re.match('(/S+)/s*(/S+)/s*(.*)')
verb = m.group(1)
title = m.group(2)
definition = m.group(3)

print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.

以下是使用自定义函数提取标题和定义的代码示例：

def extract_title_and_definition(my_string):
    """Extract the title and definition from a given string.

    Args:
        my_string: The string to extract the title and definition from.

    Returns:
        A tuple containing the title and definition.
    """

    # Find the first space character.
    space_index = my_string.find(' ')

    # Extract the verb.
    verb = my_string[:space_index]

    # Extract the title.
    start_index = space_index + 1
    end_index = my_string.find(' ', start_index)
    title = my_string[start_index:end_index]

    # Extract the definition.
    start_index = end_index + 1
    definition = my_string[start_index:]

    return verb, title, definition


my_string = "!save python Python is a high-level object oriented language created by Guido van Rossum."
verb, title, definition = extract_title_and_definition(my_string)

print(verb)  # !save
print(title)  # python
print(definition)  # Python is a high-level object oriented language created by Guido van Rossum.