我有一个简单的.csv格式数据,需要先进行操作才能创建符合此数据的绘图.但是,我理解如何从python中操作.csv格式数据.我想在R中应用相同的逻辑,但我不知道如何做到这一点.
下面是来自.csv文件的示例数据,但加载到R.我已经为我们创建了代码来讨论这个问题.
df <- data.frame(Name = c("AC", "AC", "PT", "PT", "OR", "OR"),
useless_column = c("","","A",3,4," "),
measurement = c("H", "", "K", "M", "", "H"),
amount = c(12, 54, 20, 87, 75, 22),
useless_column = c("","","A",3,4," "))
在python中,我通常会这样做:
import csv
import os
import glob
import sys
fileList = glob.glob("R:xxxxxxxxxxxxxxxxxxxxx\*.csv")
for inputFile in fileList:
outputFilename = inputFile + "output.csv"
csvInput = csv.reader(open(inputFile,'r'),delimiter=",")
outputFile = open(outputFilename,'w')
outputFile.write("Name,measurement,amount\n")
csvInput.next()
for line in csvInput:
if line[2] == "H":
meas = "100"
elif line[2] == "K":
meas = "1000"
elif line[2] == "M":
meas = "1000000"
else:
meas = "1"
amount = int(meas) * line[3]
outputFile.write(",".join(line[0],line[2],amount+"\n"]))
outputFile.close()
在python中,我可以加载csv然后使用for循环来识别csv文件中的每一行.然后在继续我的分析之前定制我的输出文件.从上面,我希望我的输出类似于下面的代码是R格式:
df <- data.frame(Name = c("AC", "AC", "PT", "PT", "OR", "OR"),
measurment = c("H", "", "K", "M", "", "H"),
amount = c(1200, 54, 20000, 87000000, 75, 2200))
我想知道在R中这样做吗?我有一个小的R代码,任何人都可以引导我进入正确的方向:
x <- read.csv("xxxx.csv", header=T,sep=",")
xC = ncol(x)
xR = nrow(x)
op = data.frame(matrix(data = x, nrow= xR, ncol=3,byrow=T))
for (x in :xC)
{
for (r in 1:xR)
{
xxxxxxxx
}
解决方法:
在R中调整python代码意味着放弃循环以支持向量化操作.在这里,我们可以根据命名向量创建meas,然后计算金额:
# dictionnary of measurement values:
m <- c(H = 100, K = 1000, M = 1000000)
# create meas based on measurement
df$meas <- m[df$measurment]
df$meas[is.na(df$meas)] <- 1
# compute amount
df$amount <- df$meas * df$amount
数据
df <- data.frame(Name = c("AC", "AC", "PT", "PT", "OR", "OR"),
measurment = c("H", "", "K", "M", "", "H"),
amount = c(1200, 54, 20000, 87000000, 75, 2200))
标签:python,r,csv 来源: https://codeday.me/bug/20190823/1702099.html
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