Convert R object to a data frame

I have an R object created lapply function within a by a by function =


     results_by_date <- by(
       data,
        data[,"Date"],
        function(subdata) {
          lapply(
          alertlevels,
          check_cutpoints2,
          data=3Dsubdata,
          mycolumn=3Dcolumn
          )
        }
     )

which has the following structure

$ 2020-08-14:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 0
 $ 2020-08-15:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 1
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 0
 $ 2020-08-16:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 15
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 6
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 6
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 6
 $ 2020-08-17:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 58
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 20
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 7
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 2
 $ 2020-08-18:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 79
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 45
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 16
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 6
 $ 2020-08-19:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 187
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 100
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 61
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 38
 $ 2020-08-20:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 121
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 31
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 13
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 4
 $ 2020-08-21:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 17
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 8
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 5
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 3
 $ 2020-08-22:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 35
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 12
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 6
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 2
 $ 2020-08-23:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 32
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 15
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 8
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 4
 $ 2020-08-24:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 15
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 5
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 1
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 0
 $ 2020-08-25:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 43
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 26
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 13
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 5
 $ 2020-08-26:List of 4
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.1
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.2
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.3
  .. ..$ NumPeopleExposed: int 0
  ..$ :List of 2
  .. ..$ criticalvalue   : num 0.4
  .. ..$ NumPeopleExposed: int 0
 - attr(*, "dim")=3D int 13
 - attr(*, "dimnames")=3DList of 1
  ..$ data[, "Date"]: chr [1:13] "2020-08-14" "2020-08-15" "2020-08-16" "20=
20-08-17" ...
 - attr(*, "call")=3D language by.data.frame(data =3D data, INDICES =3D dat=
a[, "Date"], FUN =3D function(subdata) {     lapply(alertlevels, check_cutp=
| __truncated__ ...
 - attr(*, "class")=3D chr "by"
NULL

I would like to convert the object to a dataframe. Can anyone suggest how I=
 might accomplish this task?

Thank you,
John

John David Sorkin M.D., Ph.D.
Professor of Medicine, University of Maryland School of Medicine;
Associate Director for Biostatistics and Informatics, Baltimore VA Medical =
Center Geriatrics Research, Education, and Clinical Center;=A0
Former PI Biostatistics and Informatics Core,=A0University of Maryland Scho=
ol of Medicine Claude D. Pepper Older Americans Independence Center;
Senior Statistician University of Maryland Center for Vascular Research;

Division of Gerontology, Geriatrics and Palliative Medicine,
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
Cell phone 443-418-5382