How do you learn regular expressions?

How do you learn regular expressions? Today, I finally learned the regular expression, which seems to be more difficult to understand than assembly. the symbol language is not as wide as assembly, however, it takes a lot of effort to master these symbol combination rules ...... Sometimes, when I look at books and design some expressions to match characters, I don't know myself. how do you learn regular expressions?
I finally learned the regular expression today.
It looks like a super "symbolic language" that is harder to understand than assembly. of course, its knowledge scope is not as wide as assembly. However, it takes a lot of effort to grasp these symbolic combination rules ......

Sometimes, when I look at books and design some expressions to match characters, I don't get the desired results. I am aware that I am wrong about the matching rules or meanings ..
It's really hard to remember.
I don't know how you learn regular expressions. Of course there are a lot of materials on the Internet, but they all teach you how to match strings like this.
I want to know how to learn it.
I want to match three different character combinations in a random article every day so that I can gradually become familiar with regular expressions.

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This is really not difficult to compile...
Writing analysis and judgment results using one regular condition is actually not too difficult. Its advantage is that it can be matched too well. So as long as it's not too outrageous, the cat can catch the mouse. haha
However, to write a regular expression with high efficiency, you may need to use these combinations.

If you use more, you will feel less terrible than you think.
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Try to write the collection script
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Online trial. If you play too much, you will.

Http://regexpal.com/