跟读练习: [Practice Problems] Regular Expressions (Regex) - Visually Explained - 通过视频学习英语口语
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Have you tried our regular expressions practice exercises?
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If you have, great!
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We're going to work through the solutions now.
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If not, the problems are linked in the description.
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Alright, let's start with problem one.
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In this problem, we want to match all the phone numbers from the bulletin board text.
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Each phone number follows the format.
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A fixed area code, and a hyphen, followed by three digits, another hyphen, and a final four digits.
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Since every phone number starts with the same area code and hyphen, we write the literal characters 1, 2, 3, hyphen directly into the pattern box.
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Next, the middle group of numbers can have any combination of three digits.
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To match this, we use the character class 0 through 9 to match a single digit
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and follow it with the quantifier 3 to match exactly 3.
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Following the character class, we write another literal hyphen.
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To match the last four digits, like the middle three, we use a character class with 0 through 9.
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But to match four digits instead of 3, we use a quantifier of 4.
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Great!
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As we can see, this pattern matches both phone numbers and our bulletin board text.
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Fixed quantifiers like 3 and 4 are ideal when you know the exact length you're looking for.
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Phone numbers, zip codes, product codes, anything with a predictable structure.
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Quantifiers will also be quite useful in problem 2.
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In this problem, we want to write a regular expression to match all the prices in our text string.
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each price starts with a dollar sign followed by one
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or more digits a dot
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and exactly two digits for cents you might be tempted to start by writing the literal dollar sign character
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but in regex dollar sign is a special syntax
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that means end of line
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so it won't match the dollar sign character to match a
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literal dollar sign we put a backslash in front of it after the dollar sign comes the digits before the decimal,
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which we can match using a character class with 0 through 9.
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Since there could be any number of digits before the decimal, we use the plus quantifier to match one or more digits.
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Following this character class, we specify a dot.
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Remember, like the dollar sign, the dot is special syntax, called a wildcard, that matches any single character.
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To use a literal dot character, we need to write a backslash before it.
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Finally, cents always have exactly two digits.
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To match this, we write a character class allowing the digits 0 through 9 and a quantifier of 2.
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Awesome!
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With this pattern, all five prices are matched.
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Before we move on, we've now written the character class containing 0 through 9 several times.
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Since this is such a common pattern, regex syntax actually provides a shorthand for it.
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Instead of explicitly writing the character class, we write backslash d, which also means any digit.
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Awesome, our pattern is now more concise and we still get the same matches.
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We'll use the digit shorthand backslash d again in problem 3.
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In this problem, we want to match all the dates in the text.
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Each date has a month name, a day number, and a four-digit year.
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We'll start by matching the month names.
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Month names are made up of letters, both upper and lowercase, so we'll use a character class of all the uppercase and lowercase letters.
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To match one or more letters, we follow the class with the plus quantifier.
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After the month name comes a literal space.
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After the space, the day can be one digit or two.
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To match exactly one or two digits,
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we use the backslash d shorthand followed by a range quantifier with a lower bound of one and upper bound of two.
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Following the day, we write a literal comma and space.
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Lastly, the year is always four digits, so we write the digit shorthand and a quantifier of four.
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Awesome!
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With that pattern, we've matched all the dates.
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With these practice problems, you've seen how to write patterns for three different data types.
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If you want to go deeper on any of the concepts we used in this video, check out our regular expressions intro video linked in the description.
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We're working on lots more Python explainer videos like this one, so be sure to subscribe so that you don't miss out.
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If you have any questions or topics that you'd like to learn about, let us know in the comments below.
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We'd love to hear from you.
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Thanks for watching!
关于本课
在本课中，我们将通过实际练习来掌握正则表达式的应用。这包括匹配电话号码、价格和日期等常见格式。通过实践，我们可以学会如何使用正则表达式的语法来提取文本中的信息，从而提升我们的英语理解能力。这些内容不仅对提升英语发音有帮助，也能为雅思口语练习打下良好的基础。
关键词汇与短语
- 正则表达式 - 一种用于匹配字符串的规则。
- 电话号码 - 特定格式的数字串，用于联系。
- 价格 - 带有货币符号的数字。
- 日期 - 由月份、日期和年份构成的字符串。
- 字符类 - 匹配特定类型字符的集合。
- 量词 - 指定匹配字符的数量。
- 通配符 - 用于匹配任何单个字符的符号。
- 反斜杠 - 用于转义特殊字符的符号。
练习技巧
在进行英语影子跟读时，建议你跟随视频中的节奏来模仿练习。这种 shadow speak 方法能有效提高你的英语发音和流利度。视频所用的语速适中，非常适合进行逐字跟唱。当你听到每个正则表达式的构建时，尝试大声朗读并同时理解每个部分的功能。例如，听到“字符类”时，可以即时模仿发音，并同时理解其含义。通过这样的反复练习，不仅能帮助你更好地掌握正则表达式的概念，也能提升你在实际对话中的反应能力，为雅思口语练习提供更多支持。
在模仿过程中，可以多次暂停视频，确保听懂每个术语和其应用。逐渐加快跟读速度，挑战自己的发音和语调。有意识地练习可以帮助你在真实语境中更自信地使用英语。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。