How to get data from Python to R

While working with AdWords data in R, I wanted to get data from a Python function. In those situations, rPython package comes in handy. It lets you define and execute arbitrary Python function, and get the results.

install.packages("rPython", repos = "http://www.datanalytics.com/R")

Example

Suppose you have a Python function that returns a JSON-like dictionary. Then can import it into an R data.frame as follows:

Note: it won't work if you are calling it from IPython. You should be using pure R.

library(rPython)
python.exec(c("def somefunc():", "\treturn [{'campaignId1': {'cost': {'date1': 1, 'date2': 2}, 'qs': {'date1': 1, 'date2': 2}}}, {'campaignId2': {'cost': {'date1': 1, 'date2': 2}, 'qs': {'date1': 1, 'date2': 2}}}]"))
 
y <- python.call("somefunc")
 
a <- as.data.frame(y[[1]]$campaignId1)
a
      qs cost
date1  1    1
date2  2    2
 
b <- as.data.frame(y[[2]]$campaignId2)
cbind(a,b)
      qs cost qs cost
date1  1    1  1    1
date2  2    2  2    2

In the example, I used a function that returns a dictionary equivalent to the following JSON:

[
    {
        "campaignId1": {
            "qs": {
                "date1": 1,
                "date2": 2
            },
            "cost": {
                "date1": 1,
                "date2": 2
            }
        }
    },
    {
        "campaignId2": {
            "qs": {
                "date1": 1,
                "date2": 2
            },
            "cost": {
                "date1": 1,
                "date2": 2
            }
        }
    }
]