Question

我试图弄清楚如何组合多个列，不包括NA值。

输入数据帧：

data <- data.frame(
  id = c(1:3),
  Item1 = c("Egg", "", ""),
  Item2 = c("Chicken", "Flour", ""),
  Item3 = c("", "", "Bread"),
  Item4 = c("", "Milk", "")
)

所需数据框：

desired <- data.frame(
  id = c(1:3),
  Item1 = c("Egg", "", ""),
  Item2 = c("Chicken", "Flour", ""),
  Item3 = c("", "", "Bread"),
  Item4 = c("", "Milk", ""),
  Combine = c("Egg, Chicken", "Flour, Milk", "Bread")
)

我尝试使用以下代码组合这些值：

data$Combine = paste(data$Item1, data$Item2, data$Item3, data$Item4, sep=",")

问题在于我得到的结果如下：

蛋，鸡,,
  ，面粉,,牛奶
  ，面包，

Answer 1

如果我们使用与OP帖子中类似的方法，则使用""替换带有,的前导/滞后空格，将,重复gsub的{{1}}替换为data$Combine <- gsub(",{2,}", ",", gsub("^,+|,+$", "", do.call(paste, c(data[-1], sep=",")))) data$Combine #[1] "Egg,Chicken" "Flour,Milk" "Bread" 1}}

paste

或另一种选择是使用trimws，删除前导/滞后空格（\\s+），然后使用,替换一个或多个空格（gsub） gsub("\\s+", ",", trimws(do.call(paste, data[-1]))) #[1] "Egg,Chicken" "Flour,Milk" "Bread"

data <- structure(list(ID = 1:3, Item1 = c("Egg", "", ""), Item2 = c("Chicken", 
"Flour", ""), Item3 = c("", "", "Bread"), Item4 = c("", "Milk", 
"")), .Names = c("ID", "Item1", "Item2", "Item3", "Item4"),
class = "data.frame", row.names = c(NA, -3L))

数据

apply plugin: 'base'
apply plugin: 'maven-publish'

group = 'foo.bar'
version = '1.0'

task copyPrebuilt(type: Copy) {
    from(projectDir) {
        include 'some.jar'
        rename 'some', "some-$version"
    }
    into buildDir
}

publishToMavenLocal.dependsOn copyPrebuilt

publishing {
    publications {
        prebuilt(MavenPublication) {
            artifact file("$buildDir/some-${version}.jar")
        }
    }
}

Answer 2

添加＆＃34;，＆＃34;对于非空值。

def scrape1(self):

    html = self.browser.page_source
    soup = BeautifulSoup(html, 'html.parser')
    # add links to list for later use
    urls = []
    for videos in soup.find_all('a', {'class': 'watch-now'}):
        links = videos['href']
        urls.append(links)

    return urls

def use(self):

    urls = scrape1()

创建新列。

data1 <- sapply(data[-1], function(x) ifelse(x != "", paste(x, " ", sep = ","), ""))

data1 <- data.frame(id = c(1:3), data1)

剪掉最后的符号。

data$Combine <- paste0(data1$Item1, data1$Item2, data1$Item3, data1$Item4)

合并多个列，不包括空值

2 个答案:

数据