Jupyter 笔记本：Package 或 loadNamespace 中“插入符号”的命名空间加载失败

Question

I was originally going to ask the following question but I figured it out myself and decided to post the following question and answer in case it might help someone with the same issue:

I'm currently working on a project in Jupyter Notebook using R.

Everything was working fine until I try to load caret with library(caret) and I get the following error message:

Error: package or namespace load failed for 'caret' in loadNamespace(j <- i[[1L]], c(lib.loc, > > .libPaths()), versionCheck = vI[[j]]):
there is no package called 'codetools'
Traceback:

1. library(caret)
2. tryCatch({
.     attr(package, "LibPath") <- which.lib.loc
.     ns <- loadNamespace(package, lib.loc)
 .     env <- attachNamespace(ns, pos = pos, deps, exclude, include.only)
 . }, error = function(e) {
 .     P <- if (!is.null(cc <- conditionCall(e))) 
 .         paste(" in", deparse(cc)[1L])
 .     else ""
 .     msg <- gettextf("package or namespace load failed for %s%s:\n %s", 
 .         sQuote(package), P, conditionMessage(e))
 .     if (logical.return) 
 .         message(paste("Error:", msg), domain = NA)
 .     else stop(msg, call. = FALSE, domain = NA)
 . })
3. tryCatchList(expr, classes, parentenv, handlers)
4. tryCatchOne(expr, names, parentenv, handlers[[1L]])
5. value[[3L]](cond)
6. stop(msg, call. = FALSE, domain = NA)

I've tried unistalling and re-installing caret in RStudio but that didn't help either. What makes this more infuriating is that in my RStudio everything is working fine, it's just Jypyter notebook that is unable to find caret .

Here is my session info FYI:

R version 3.6.0 (2019-04-26)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 15063)

Matrix products: default

locale:
[1] LC_COLLATE=English_United Kingdom.1252 
[2] LC_CTYPE=English_United Kingdom.1252   
[3] LC_MONETARY=English_United Kingdom.1252
[4] LC_NUMERIC=C                           
[5] LC_TIME=English_United Kingdom.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] ggplot2_3.3.0   lattice_0.20-38

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.3        pillar_1.4.2      compiler_3.6.0    plyr_1.8.4       
 [5] base64enc_0.1-3   iterators_1.0.12  tools_3.6.0       digest_0.6.22    
 [9] uuid_0.1-2        jsonlite_1.6      evaluate_0.14     tibble_2.1.3     
[13] gtable_0.3.0      nlme_3.1-142      pkgconfig_2.0.3   rlang_0.4.5      
[17] foreach_1.4.7     IRdisplay_0.7.0   IRkernel_1.0.2    repr_1.0.1       
[21] withr_2.1.2       dplyr_0.8.3       grid_3.6.0        tidyselect_0.2.5 
[25] glue_1.3.1        R6_2.4.1          pbdZMQ_0.3-3      purrr_0.3.3      
[29] magrittr_1.5      scales_1.0.0      codetools_0.2-16  htmltools_0.4.0  
[33] assertthat_0.2.1  timeDate_3043.102 colorspace_1.4-1  munsell_0.5.0    
[37] crayon_1.3.4     
​```

Answer 1

I solved the issue by uninstalling caret with remove.packages("caret") in Jupyter Notebook. I also checked that the package was no longer installed in RStudio.

Then, I re-installed caret with install.packages("caret", dependencies = TRUE) in Jupyter notebook.

I think what was causing the issue was that somehow Jupyter had not installed caret 's dependent packages. From the first error message in the question,this was codetools . And every time I installed the package named in the error, it came up with another package to install. Which made me think that - of course- it hadn't installed any of the dependencies.

caret now works in Jupyter Notebook.