Convert Json array key's as csv column name and values - json

Question

I am parsing a json data to write a csv file. I am using tidyjson package to do this work.
In some point I need to print all the subjects value below in a separate columns and score as a value. Meaning Physics, Mathematics will be a column name and score will be there value.
{
"results": {
"subjects": [
{
"subject": {
"name": "Physics",
"code": "PHY"
},
"score": 70
},
{
"subject": {
"name": "Mathematics",
"code": "MATH"
},
"score": 50
}
]
}
}
I have tried as below:
json_data %>%
as.tbl_json %>%
gather_array %>%
spread_values(user_id = jstring("user_id")) %>%
enter_object("results") %>%
enter_object("subjects") %>%
gather_array("subjects") %>%
spread_values(score = jstring("score")) %>%
enter_object("subject") %>%
spread_values(subject = jstring("subject")) %>%
mutate(Physics = case_when(.$name == "Physics" ~ score)) %>%
mutate(Mathematics = case_when(.$name == "Mathematics" ~ score))
But this shows multiple rows for one student. I need to show single row with each subject and score as a column value.

Answer 1

But this shows multiple rows for one student. I need to show single row with each subject and score as a column value.
That means, your need a unique row based on subject name? In that case you can use aggregate
if you have a data frame named df like,
subject <- c("phy", "math", "phy", "math")
Score <- c(10, NA, NA, 20)
df <- data.frame(subject, Score)
then,
aggregate(x=df[c("Score")], by=list(subjectName=df$subject), max, na.rm = TRUE)
output
subjectName Score
phy 10
math 20