R - 从两个单词的字符串中提取城市名称
R - Extract city name from two-word strings
我正在使用包含如下城市名称的数据库：
cities <- c("Fairhope 3NE", "Gadsden 19N", "Selma 13 WNW", "Batesville 8 WNW",
"Elgin 5 S", "Tucson 11 W", "Williams 35 NNW", "Fallbrook 5 NE",
"Stovepipe Wells 1 SW", "Cortez 8 SE", "La Junta 17 WSW", "Montrose 11 ENE",
"Everglades City 5 NE", "Sebring 23 SSE", "Brunswick 23 S", "Newton 11 SW",
"Newton 8 W", "Watkinsville 5 SSE", "Des Moines 17 E", "Champaign 9 SW",
"Shabbona 5 NNE", "Bedford 5 WNW", "Manhattan 6 SSW", "Oakley 19 SSW",
"Bowling Green 21 NNE", "Versailles 3 NNW", "Lafayette 13 SE",
"Monroe 26 N", "Goodridge 12 NNW", "Chillicothe 22 ENE", "Joplin 24 N",
"Salem 10 W", "Holly Springs 4 N", "Newton 5 ENE", "Asheville 13 S",
"Asheville 8 SSW", "Durham 11 W", "Jamestown 38 WSW", "Medora 7 E",
"Northgate 5 ESE", "Harrison 20 SSE", "Lincoln 11 SW", "Lincoln 8 ENE",
"Whitman 5 ENE", "Las Cruces 20 N", "Los Alamos 13 W", "Socorro 20 N",
"Mercury 3 SSW", "Coshocton 8 NNE", "Goodwell 2 E", "Stillwater 2 W",
"Stillwater 5 WNW", "Coos Bay 8 SW", "Corvallis 10 SSW", "Riley 10 WSW",
"Blackville 3 W", "McClellanville 7 NE", "Aberdeen 35 WNW", "Buffalo 13 ESE",
"Pierre 24 S", "Sioux Falls 14 NNE", "Crossville 7 NW", "Austin 33 NW",
"Bronte 11 NNE", "Edinburg 17 NNE", "Monahans 6 ENE", "Muleshoe 19 S",
"Palestine 6 WNW", "Panther Junction 2 N", "Necedah 5 WNW")
我只想提取城市名称。以下代码适用于某些情况：
gsub( " .*$", "", cities)
但对于具有两个单词名称的城市，例如 Stovepipe Wells 1 SW 和 La Junta 17 WSW。
，它会失败
对于这些情况有什么解决方案吗？
您可以删除所有以数字开头的子字符串：
> sub("\s*\d.*", "", cities)
[1] "Fairhope" "Gadsden" "Selma" "Batesville" "Elgin" "Tucson" "Williams" "Fallbrook" "Stovepipe Wells"
[10] "Cortez" "La Junta" "Montrose" "Everglades City" "Sebring" "Brunswick" "Newton" "Newton" "Watkinsville"
[19] "Des Moines" "Champaign" "Shabbona" "Bedford" "Manhattan" "Oakley" "Bowling Green" "Versailles" "Lafayette"
[28] "Monroe" "Goodridge" "Chillicothe" "Joplin" "Salem" "Holly Springs" "Newton" "Asheville" "Asheville"
[37] "Durham" "Jamestown" "Medora" "Northgate" "Harrison" "Lincoln" "Lincoln" "Whitman" "Las Cruces"
[46] "Los Alamos" "Socorro" "Mercury" "Coshocton" "Goodwell" "Stillwater" "Stillwater" "Coos Bay" "Corvallis"
[55] "Riley" "Blackville" "McClellanville" "Aberdeen" "Buffalo" "Pierre" "Sioux Falls" "Crossville" "Austin"
[64] "Bronte" "Edinburg" "Monahans" "Muleshoe" "Palestine" "Panther Junction" "Necedah"
>
这里，
\s* - 匹配 0+ 个空格\d - 一个数字.* - 字符串的其余部分。
参见regex demo。 sub 只执行一次匹配和替换操作。
这应该有效：
gsub( " [1-9].*$", "", cities)
你可以使用
gsub("(\D+)\s+.*", "\1", cities)
屈服
[1] "Fairhope" "Gadsden" "Selma" "Batesville" "Elgin"
[6] "Tucson" "Williams" "Fallbrook" "Stovepipe Wells" "Cortez"
[11] "La Junta" "Montrose" "Everglades City" "Sebring" "Brunswick"
[16] "Newton" "Newton" "Watkinsville" "Des Moines" "Champaign"
[21] "Shabbona" "Bedford" "Manhattan" "Oakley" "Bowling Green"
[26] "Versailles" "Lafayette" "Monroe" "Goodridge" "Chillicothe"
[31] "Joplin" "Salem" "Holly Springs" "Newton" "Asheville"
[36] "Asheville" "Durham" "Jamestown" "Medora" "Northgate"
[41] "Harrison" "Lincoln" "Lincoln" "Whitman" "Las Cruces"
[46] "Los Alamos" "Socorro" "Mercury" "Coshocton" "Goodwell"
[51] "Stillwater" "Stillwater" "Coos Bay" "Corvallis" "Riley"
[56] "Blackville" "McClellanville" "Aberdeen" "Buffalo" "Pierre"
[61] "Sioux Falls" "Crossville" "Austin" "Bronte" "Edinburg"
[66] "Monahans" "Muleshoe" "Palestine" "Panther Junction" "Necedah"
解释一下，这说：
(\D+) # not a digit, 1+ times
\s+ # at least one whitespace
.* # rest of the string
这将由第一个捕获的组替换，在本例中为 \1。
假设每个字符串以相同的模式结尾：
- space
- 位数
- 可选space,
ENSW
gsub(" \d+ ?[ENSW]+$", "", cities)
结果：
[1] "Fairhope" "Gadsden" "Selma" "Batesville"
[5] "Elgin" "Tucson" "Williams" "Fallbrook"
[9] "Stovepipe Wells" "Cortez" "La Junta" "Montrose"
[13] "Everglades City" "Sebring" "Brunswick" "Newton"
[17] "Newton" "Watkinsville" "Des Moines" "Champaign"
[21] "Shabbona" "Bedford" "Manhattan" "Oakley"
[25] "Bowling Green" "Versailles" "Lafayette" "Monroe"
[29] "Goodridge" "Chillicothe" "Joplin" "Salem"
[33] "Holly Springs" "Newton" "Asheville" "Asheville"
[37] "Durham" "Jamestown" "Medora" "Northgate"
[41] "Harrison" "Lincoln" "Lincoln" "Whitman"
[45] "Las Cruces" "Los Alamos" "Socorro" "Mercury"
[49] "Coshocton" "Goodwell" "Stillwater" "Stillwater"
[53] "Coos Bay" "Corvallis" "Riley" "Blackville"
[57] "McClellanville" "Aberdeen" "Buffalo" "Pierre"
[61] "Sioux Falls" "Crossville" "Austin" "Bronte"
[65] "Edinburg" "Monahans" "Muleshoe" "Palestine"
[69] "Panther Junction" "Necedah"
这个正则表达式应该适用于任何地方，包括 R：.+?(?=\ \d)
它包括第一个 space 后跟一个数字之前的所有内容。
我正在使用包含如下城市名称的数据库：
cities <- c("Fairhope 3NE", "Gadsden 19N", "Selma 13 WNW", "Batesville 8 WNW",
"Elgin 5 S", "Tucson 11 W", "Williams 35 NNW", "Fallbrook 5 NE",
"Stovepipe Wells 1 SW", "Cortez 8 SE", "La Junta 17 WSW", "Montrose 11 ENE",
"Everglades City 5 NE", "Sebring 23 SSE", "Brunswick 23 S", "Newton 11 SW",
"Newton 8 W", "Watkinsville 5 SSE", "Des Moines 17 E", "Champaign 9 SW",
"Shabbona 5 NNE", "Bedford 5 WNW", "Manhattan 6 SSW", "Oakley 19 SSW",
"Bowling Green 21 NNE", "Versailles 3 NNW", "Lafayette 13 SE",
"Monroe 26 N", "Goodridge 12 NNW", "Chillicothe 22 ENE", "Joplin 24 N",
"Salem 10 W", "Holly Springs 4 N", "Newton 5 ENE", "Asheville 13 S",
"Asheville 8 SSW", "Durham 11 W", "Jamestown 38 WSW", "Medora 7 E",
"Northgate 5 ESE", "Harrison 20 SSE", "Lincoln 11 SW", "Lincoln 8 ENE",
"Whitman 5 ENE", "Las Cruces 20 N", "Los Alamos 13 W", "Socorro 20 N",
"Mercury 3 SSW", "Coshocton 8 NNE", "Goodwell 2 E", "Stillwater 2 W",
"Stillwater 5 WNW", "Coos Bay 8 SW", "Corvallis 10 SSW", "Riley 10 WSW",
"Blackville 3 W", "McClellanville 7 NE", "Aberdeen 35 WNW", "Buffalo 13 ESE",
"Pierre 24 S", "Sioux Falls 14 NNE", "Crossville 7 NW", "Austin 33 NW",
"Bronte 11 NNE", "Edinburg 17 NNE", "Monahans 6 ENE", "Muleshoe 19 S",
"Palestine 6 WNW", "Panther Junction 2 N", "Necedah 5 WNW")
我只想提取城市名称。以下代码适用于某些情况：
gsub( " .*$", "", cities)
但对于具有两个单词名称的城市，例如 Stovepipe Wells 1 SW 和 La Junta 17 WSW。
对于这些情况有什么解决方案吗？
您可以删除所有以数字开头的子字符串：
> sub("\s*\d.*", "", cities)
[1] "Fairhope" "Gadsden" "Selma" "Batesville" "Elgin" "Tucson" "Williams" "Fallbrook" "Stovepipe Wells"
[10] "Cortez" "La Junta" "Montrose" "Everglades City" "Sebring" "Brunswick" "Newton" "Newton" "Watkinsville"
[19] "Des Moines" "Champaign" "Shabbona" "Bedford" "Manhattan" "Oakley" "Bowling Green" "Versailles" "Lafayette"
[28] "Monroe" "Goodridge" "Chillicothe" "Joplin" "Salem" "Holly Springs" "Newton" "Asheville" "Asheville"
[37] "Durham" "Jamestown" "Medora" "Northgate" "Harrison" "Lincoln" "Lincoln" "Whitman" "Las Cruces"
[46] "Los Alamos" "Socorro" "Mercury" "Coshocton" "Goodwell" "Stillwater" "Stillwater" "Coos Bay" "Corvallis"
[55] "Riley" "Blackville" "McClellanville" "Aberdeen" "Buffalo" "Pierre" "Sioux Falls" "Crossville" "Austin"
[64] "Bronte" "Edinburg" "Monahans" "Muleshoe" "Palestine" "Panther Junction" "Necedah"
>
这里，
\s*- 匹配 0+ 个空格\d- 一个数字.*- 字符串的其余部分。
参见regex demo。 sub 只执行一次匹配和替换操作。
这应该有效：
gsub( " [1-9].*$", "", cities)
你可以使用
gsub("(\D+)\s+.*", "\1", cities)
屈服
[1] "Fairhope" "Gadsden" "Selma" "Batesville" "Elgin"
[6] "Tucson" "Williams" "Fallbrook" "Stovepipe Wells" "Cortez"
[11] "La Junta" "Montrose" "Everglades City" "Sebring" "Brunswick"
[16] "Newton" "Newton" "Watkinsville" "Des Moines" "Champaign"
[21] "Shabbona" "Bedford" "Manhattan" "Oakley" "Bowling Green"
[26] "Versailles" "Lafayette" "Monroe" "Goodridge" "Chillicothe"
[31] "Joplin" "Salem" "Holly Springs" "Newton" "Asheville"
[36] "Asheville" "Durham" "Jamestown" "Medora" "Northgate"
[41] "Harrison" "Lincoln" "Lincoln" "Whitman" "Las Cruces"
[46] "Los Alamos" "Socorro" "Mercury" "Coshocton" "Goodwell"
[51] "Stillwater" "Stillwater" "Coos Bay" "Corvallis" "Riley"
[56] "Blackville" "McClellanville" "Aberdeen" "Buffalo" "Pierre"
[61] "Sioux Falls" "Crossville" "Austin" "Bronte" "Edinburg"
[66] "Monahans" "Muleshoe" "Palestine" "Panther Junction" "Necedah"
解释一下，这说：
(\D+) # not a digit, 1+ times
\s+ # at least one whitespace
.* # rest of the string
这将由第一个捕获的组替换，在本例中为 \1。
假设每个字符串以相同的模式结尾：
- space
- 位数
- 可选space,
ENSW的组合
gsub(" \d+ ?[ENSW]+$", "", cities)
结果：
[1] "Fairhope" "Gadsden" "Selma" "Batesville"
[5] "Elgin" "Tucson" "Williams" "Fallbrook"
[9] "Stovepipe Wells" "Cortez" "La Junta" "Montrose"
[13] "Everglades City" "Sebring" "Brunswick" "Newton"
[17] "Newton" "Watkinsville" "Des Moines" "Champaign"
[21] "Shabbona" "Bedford" "Manhattan" "Oakley"
[25] "Bowling Green" "Versailles" "Lafayette" "Monroe"
[29] "Goodridge" "Chillicothe" "Joplin" "Salem"
[33] "Holly Springs" "Newton" "Asheville" "Asheville"
[37] "Durham" "Jamestown" "Medora" "Northgate"
[41] "Harrison" "Lincoln" "Lincoln" "Whitman"
[45] "Las Cruces" "Los Alamos" "Socorro" "Mercury"
[49] "Coshocton" "Goodwell" "Stillwater" "Stillwater"
[53] "Coos Bay" "Corvallis" "Riley" "Blackville"
[57] "McClellanville" "Aberdeen" "Buffalo" "Pierre"
[61] "Sioux Falls" "Crossville" "Austin" "Bronte"
[65] "Edinburg" "Monahans" "Muleshoe" "Palestine"
[69] "Panther Junction" "Necedah"
这个正则表达式应该适用于任何地方，包括 R：.+?(?=\ \d)
它包括第一个 space 后跟一个数字之前的所有内容。