Extract numerical value before a string in R
I have been mucking around with regex strings and strsplit but can't figure out how to solve my problem.
I have a collection of html documents that will always contain the phrase "people own these". I want to extract the number immediately preceding this phrase. i.e. '732,234 people own these' - I'm hoping to capture the number 732,234 (including the comma, though I don't care if it's removed).
The number and phrase are always surrounded by a . I tried using Xpath but that seemed even harder than a regex expression. Any help or advice is greatly appreciated!
example string: >742,811 people own these<
-> 742,811
r
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
add a comment |
I have been mucking around with regex strings and strsplit but can't figure out how to solve my problem.
I have a collection of html documents that will always contain the phrase "people own these". I want to extract the number immediately preceding this phrase. i.e. '732,234 people own these' - I'm hoping to capture the number 732,234 (including the comma, though I don't care if it's removed).
The number and phrase are always surrounded by a . I tried using Xpath but that seemed even harder than a regex expression. Any help or advice is greatly appreciated!
example string: >742,811 people own these<
-> 742,811
r
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
1
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46
add a comment |
I have been mucking around with regex strings and strsplit but can't figure out how to solve my problem.
I have a collection of html documents that will always contain the phrase "people own these". I want to extract the number immediately preceding this phrase. i.e. '732,234 people own these' - I'm hoping to capture the number 732,234 (including the comma, though I don't care if it's removed).
The number and phrase are always surrounded by a . I tried using Xpath but that seemed even harder than a regex expression. Any help or advice is greatly appreciated!
example string: >742,811 people own these<
-> 742,811
r
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
I have been mucking around with regex strings and strsplit but can't figure out how to solve my problem.
I have a collection of html documents that will always contain the phrase "people own these". I want to extract the number immediately preceding this phrase. i.e. '732,234 people own these' - I'm hoping to capture the number 732,234 (including the comma, though I don't care if it's removed).
The number and phrase are always surrounded by a . I tried using Xpath but that seemed even harder than a regex expression. Any help or advice is greatly appreciated!
example string: >742,811 people own these<
-> 742,811
r
r
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
edited Nov 14 '18 at 2:45
hrbrmstr
60.8k688150
60.8k688150
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
asked Nov 14 '18 at 2:19
PermafrostPermafrost
275
275
1
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46
add a comment |
1
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46
1
1
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46
add a comment |
2 Answers
2
active
oldest
votes
Try using str_extract_all from the stringr library:
str_extract_all(data, "\d1,3(?:,\d3)*(?:\.\d+)?(?= people own these)")
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
add a comment |
Could you please try following.
val <- "742,811 people own these"
gsub(' [a-zA-Z]+',"",val)
Output will be as follows.
[1] "742,811"
Explanation: using gsub(global substitution) function of R here. Putting condition here where it should replace all occurrences of space with small or capital alphabets with NULL for variable val.
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
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active
oldest
votes
Try using str_extract_all from the stringr library:
str_extract_all(data, "\d1,3(?:,\d3)*(?:\.\d+)?(?= people own these)")
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
add a comment |
Try using str_extract_all from the stringr library:
str_extract_all(data, "\d1,3(?:,\d3)*(?:\.\d+)?(?= people own these)")
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
add a comment |
Try using str_extract_all from the stringr library:
str_extract_all(data, "\d1,3(?:,\d3)*(?:\.\d+)?(?= people own these)")
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
Try using str_extract_all from the stringr library:
str_extract_all(data, "\d1,3(?:,\d3)*(?:\.\d+)?(?= people own these)")
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
edited Nov 14 '18 at 2:32
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
answered Nov 14 '18 at 2:26
Tim BiegeleisenTim Biegeleisen
224k1391143
224k1391143
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
add a comment |
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
It works nearly perfectly, returns a large list of empty characters and the value i'm after. Is there any reason it seems to return a bunch of listed NA's as well?
– Permafrost
Nov 14 '18 at 3:02
2
2
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost: How could anyone know the answer to that question, given the lack of any example?
– 42-
Nov 14 '18 at 3:09
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
@Permafrost I'm not in front of an R console at the moment, but I would suggest starting with a smaller test text, and see if you can do some debugging.
– Tim Biegeleisen
Nov 14 '18 at 3:11
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
Thanks very much, I was just after a quick fix so I used 'str_extract' to return a character vector not a list, then used x[!is.na(x)] (where x is the character vector) to remove the NA's and get the final value. I'll keep reading up on Xpath, but this is a fast way to get what I need.
– Permafrost
Nov 14 '18 at 4:31
add a comment |
Could you please try following.
val <- "742,811 people own these"
gsub(' [a-zA-Z]+',"",val)
Output will be as follows.
[1] "742,811"
Explanation: using gsub(global substitution) function of R here. Putting condition here where it should replace all occurrences of space with small or capital alphabets with NULL for variable val.
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
add a comment |
Could you please try following.
val <- "742,811 people own these"
gsub(' [a-zA-Z]+',"",val)
Output will be as follows.
[1] "742,811"
Explanation: using gsub(global substitution) function of R here. Putting condition here where it should replace all occurrences of space with small or capital alphabets with NULL for variable val.
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
add a comment |
Could you please try following.
val <- "742,811 people own these"
gsub(' [a-zA-Z]+',"",val)
Output will be as follows.
[1] "742,811"
Explanation: using gsub(global substitution) function of R here. Putting condition here where it should replace all occurrences of space with small or capital alphabets with NULL for variable val.
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
Could you please try following.
val <- "742,811 people own these"
gsub(' [a-zA-Z]+',"",val)
Output will be as follows.
[1] "742,811"
Explanation: using gsub(global substitution) function of R here. Putting condition here where it should replace all occurrences of space with small or capital alphabets with NULL for variable val.
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
answered Nov 14 '18 at 2:25
RavinderSingh13RavinderSingh13
27.4k41538
27.4k41538
add a comment |
add a comment |
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1
Please do not use regular expressions to work with HTML. Can you please post a representative sample of the actual HTML or a link to the source? You should be using XML operations. It's kind of sad two folks are aiding this path fraught with peril.
– hrbrmstr
Nov 14 '18 at 2:46