stata - 在句子中查找单词并创建指示变量

Question

我有一个带有各种句子的变量：

Cats are good pets, for they are clean and are not noisy.
Abstraction is often one floor above you.
She wrote a long letter to Charlie, but he didn't read it.
Where do random thoughts come from?
Mary plays the piano.
I want more detailed information.
I'd rather be a bird than a fish.
When I was little I had a car door slammed shut on my hand. I still remember it quite vividly.
Malls are great places to shop; John can find everything he needs under one roof.
My Mum tries to be cool by saying that she likes all the same things that I do.

name == 1如果找到名称，如何创建变量？

name == 2如果句子中的任何单词与我选择的单词匹配（例如letter） ，我也希望有变量。

我尝试了以下方法：

gen name = regexm(sentence, "letter* & (Charlie | Mary | John)*")` 

但是，这不起作用。我只得到name == 0所有的观察。

标签： stata

Answer 1

正则表达式很棒，但 Catch-22 是您必须非常努力地学习该语言；如果你精通了，那么你就会看到好处。

我将把它留给其他答案来提供智能正则表达式解决方案。这里的目的是强调其他字符串函数也可以使用。在这里，我利用了一个事实strpos()，如果它在另一个字符串中找到一个字符串，则返回一个肯定的结果，相当于 true。此外，Stata 将解析成单词，因此即使（例如）当且仅当它是一个单词时才找到一个字符串，从第一原理来看并不太难。

clear 
input strL whatever 
"Cats are good pets, for they are clean and are not noisy."
"Abstraction is often one floor above you."
"She wrote a long letter to Charlie, but he didn't read it."
"Where do random thoughts come from?"
"Mary plays the piano."
"I want more detailed information."
"I'd rather be a bird than a fish."
"When I was little I had a car door slammed shut on my hand. I still remember it quite vividly."
"Malls are great places to shop; John can find everything he needs under one roof."
"My Mum tries to be cool by saying that she likes all the same things that I do."
end 

gen wanted1 = strpos(whatever, "Charlie") | strpos(whatever, "Mary") | strpos(whatever, "John") 

* cat or cats as a word 
gen wanted2 = 0 
gen wordcount = wordcount(whatever) 
su wordcount, meanonly 
local J = r(max) 
quietly foreach w in cat cats { 
    forval j = 1/`J' { 
        replace wanted2 = 1 if word(lower(whatever), `j') == "`w'" 
    }
} 

gen what = substr(whatever, 1, 40) 
list wanted? what, sep(0) 

     +--------------------------------------------------------------+
     | wanted1   wanted2                                       what |
     |--------------------------------------------------------------|
  1. |       0         1   Cats are good pets, for they are clean a |
  2. |       0         0   Abstraction is often one floor above you |
  3. |       1         0   She wrote a long letter to Charlie, but  |
  4. |       0         0        Where do random thoughts come from? |
  5. |       1         0                      Mary plays the piano. |
  6. |       0         0          I want more detailed information. |
  7. |       0         0          I'd rather be a bird than a fish. |
  8. |       0         0   When I was little I had a car door slamm |
  9. |       1         0   Malls are great places to shop; John can |
 10. |       0         0   My Mum tries to be cool by saying that s |
     +--------------------------------------------------------------+