R, Setting up a loop to continuously collect JSON - json

Question

I am trying to set up an R script that will continuously collect JSON data(every 15secs throughout the day) from OpenSky's REST API.
I am trying to adapt this script meant to collect Car2Go data.
I think I have the basics for the loop, however, I am confusing myself in combining all the data into on dataframe that will can write to a csv at the end up the day.
library(tidyverse)
library(jsonlite)
for (day in 1:100){
flight.df.time <- data.frame()
for (i in seq(1,5760)){
rm(flight.df)
flight.df <- data.frame()
all_flights <- fromJSON('https://opensky-network.org/api/states/all')
# Creates df from JSON and filters lat/long to DC Metro Area
dc_flights <- as.data.frame(all_flights$states) %>%
mutate(V6 = as.numeric(levels(V6))[V6],
V7 = as.numeric(levels(V7))[V7]) %>%
filter(between(V6, -78.361647, -75.872761),
between(V7, 38.197760, 39.646129))
flight.df.time <- rbind(dc_flights, flight.df)
print(Sys.time())
Sys.sleep(15)
}
write.csv(flight.df.time, file = paste(day, '_flight.csv', sep = ''))
}
Would anyone be able to help me get the loop to continuously add data to the data frame and not overwrite it like I am doing now? Thanks!

Answer 1

library(tidyverse)
library(jsonlite)
flight.df.time <- data.frame(icao24 = character(),
callsign = character(),
origin_country = character(),
time_position = double(),
time_velocity = double(),
longitude = double(),
latitude = double(),
altitude = double(),
on_ground = character(),
velocity = double(),
heading = double(),
vertical_rate = double(),
sensors = character(),
Time = character(),
stringsAsFactors = FALSE)
write.table(flight.df.time,'G:/DCIST/OpenSky/Data/flight_week.csv', sep = ",", row.names = FALSE)
for (day in 1:100){
for (i in seq(1, 8640)){
rm(flight.df)
flight.df <- data.frame()
flight_url <- 'https://opensky-network.org/api/states/all'
tryCatch({
all_flights <- fromJSON(txt = flight_url)
}, error=function(e){cat("ERROR :",conditionMessage(e), "\n")})
dc_flights <- as.data.frame(all_flights$states) %>%
select(-(V14:V18)) %>%
mutate(V6 = as.numeric(levels(V6))[V6],
V7 = as.numeric(levels(V7))[V7],
Time = Sys.time()) %>%
filter(between(V6, -78.361647, -75.872761),
between(V7, 38.197760, 39.646129))
flight.df.time <- rbind(dc_flights, flight.df)
write.table(flight.df.time,'G:/DCIST/OpenSky/Data/flight_week.csv', append = TRUE, sep = ",", col.names = FALSE, row.names = FALSE)
print(Sys.time())
Sys.sleep(10)
}
}