Question

How can I find number of rows in a dataframe, and how to find the number of rows that dont have null values

Answer 1

To know the number of columns in a dataframe use the function NCOL()

To omit the null value indexes out of the result use the function NCOL(na.omit(data_frame_name))

Answer 2

Use nrow() to find number of rows and ncol() or length() to find the number of columns in a dataframe.

Try using nrow(df) - length(which(is.na(df))) to find number of rows with no nulls.