How to un-delete cells in Jupyter Lab? - jupyter-notebook

Can it be done?
"Undo" only seems to work for blocks/lines of code within a cell
Cheers

Option 1
Edit > Undo Cell Operation (or using the shortcut Z in the command mode - to access the command mode press ESC)
or
Edit > Undo (or using the shortcut CTRL+Z)
Option 2
Alternatively, if one didn't restart the kernel, one can export the IPython history by running
%history -g # If one wants to give a name to the file add "-f NAME"
Or access the content of all cells (including deleted ones) with _ih such as
_ih[-10:]
Option 3
If one already restarted the kernel, File > Revert Notebook to Checkpoint
Checkpoints will be stored in .ipynb_checkpoints so one can look inside the files and see if the deleted cell is there.

Related

Customizing Powerleve10k prompt

I just added the Powerlevel10k theme to my zsh and i'm trying to configure certain parts.
It currently looks like this:
The ~/.p10k.zsh has a lot of configurations done and I've been trying to change certain things but i'm not there yet.
I don't want to print the whole path on the left prompt, just the directory. Also, not sure what those numbers indicate in the git section. And the right prompt is displaying my ruby version, although I haven't used Ruby in ages and want to change it to a different setting.
I've tried adding a PS1=... to .zshrc but it seems to be overriden by the P10K config file.
Any suggestions?
Display only the last directory segment
Open ~/.p10k.zsh.
Search for POWERLEVEL9K_SHORTEN_STRATEGY.
Change the value of this parameter to truncate_to_last.
Alternatively, change the value of POWERLEVEL9K_DIR_MAX_LENGTH to 1. This will maximally shorten current directory while keeping the transformation reversible. You can restore the original directory by copy-pasting the shortened directory to the command line and pressing TAB.
Ruby version
Powerlevel10k has several prompt segments that can display Ruby version. By default only those are enabled that display Ruby version when it has been manually overridden by some tool (e.g., rbenv or asdf).
To remove Ruby version from prompt:
Open ~/.p10k.zsh.
Search for POWERLEVEL9K_RIGHT_PROMPT_SEGMENTS.
Remove or comment out the following elements: rbenv, rvm and asdf.
Alternatively (and perhaps preferably), find out which tool is overriding Ruby version for you and remove the override if you no longer need it.
shorten dir segment to show only deepest directory
To show only last n significant path segments, you can set following in your config .zshrc, e.g n=1 means show only last folder in present working directory:
POWERLEVEL9K_SHORTEN_DIR_LENGTH=1
See https://stackoverflow.com/a/49027654
explain Git symbols
The question/exclamation mark in Git segment (vcs segment, next to path) means the number of files untracked (?) and unstaged (!). For detailed description see What do different symbols in Git status mean?
change version segment
You can change the version segment (on the right of prompt) to reflect another tool. For example to replace shown ruby version by python version replace the element within right promt elements in your config .zshrc:
POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(rbenv)
by
POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(pyenv)

How to scroll up in Vim buffer with R (using Nvim-R)

I'm a happy user of the Nvim-R plugin, but I cannot find out how to scroll up in the buffer window that the plugin opens with R. Say for instance that I have a large output in console, but I cannot see the top of it - how do I scroll up to see this? In tmux for instance there's a copy mode that quite handily lets you do this, but how is this done in the R buffer?
An example below where I'm very curious to see what's on the line above the one begining with "is.na(a)...". How can this be achieved?
I have scoured the documentation found here, but without luck.
The answer is apparently to use Ctrl+\ Ctrl+n according to this answer on the bugreports for NVim-R.
Here's what my output looks like when I output mtcars:
When I hit Ctrl+\ Ctrl+n, I can move the cursor and I get line numbers:
To get back to interactive, I just use i, the same way I normally would.
Apparently, if you are using neovim, then you can add let R_esc_term = 0 in your ~/.vimrc file and you can then use the escape key, but if you don't use neovim, you are stuck using the two ctrl commands ¯\_(ツ)_/¯.
As pointed out by ZNK, it is about switching to normal mode in Vim's terminal. This, however, can easily fail due to cumbersome keybinding. If such is the case, remap the default keybinding to something reasonable, say, by putting this in your .vimrc:
tnoremap jk <C-\><C-n>
This works for me in Linux running Vim 8.0 in terminal (e.g. does not require Neovim). As you can see, I use 'jk' to switch from insert to normal mode. One can use Esc instead of jk, however, this makes me unable to use up arrow to retrieve command line history as been reported elsewhere.

How do I set the size of the history file in sqlite3?

So I'm using sqlite3 on Unix,and I'd like to resize my sqlite3 command history to 999999. Is there a way to do this?
The SQLITE_HISTORY environment variable, if it exists, specifies
the name of the command-line editing history file
To repeat the last command, just press the ↑ key, to search for older
ones — use Ctrl+R shortcut. History search It's faster to find a query than to type it again
By default, SQLite stores the history file in the user’s home directory
and names it .sqlite_history It’s in plain text, so you can view it
in your favorite editor. If you prefer to save it elsewhere, specify
the full path in the SQLITE_HISTORY environment variable.
source: https://antonz.org/sqlite-history
e.g: size using nano CTRL + Shift + 6 to mark block move cursor then CTRL + K to cut/del block/line
cd ~
nano .sqlite_history
or
split --verbose -l1000 .sqlite_history .sqlite_history.

display problems of zsh in archlinux

Currently I have installed zsh in archlinux (in gnome 3), and every time when I open the terminal, there are 3 "???" before, then I have to change it manually on the options
Actually I have already set the default locale to UTF-8, and it works in the console before I enter the gnome.But after I enter the gnome interface, it did not work.
After I have changed that, it works, but there is another problem, everytime I type a command and press tab, all the command will be shifted right by 2 words, for example if I type ls, it will display like this:
ls becomes lsls
vim becomes vivim
The first 2 letters cannot be cleared, which is very annoying, can anyone help me about this? Thanks
I finally got how to solve this question
After we enabled the locale in the /etc/locale.gen and use locale-gen to generate it. I have to also set the locale system-wide,
create the /etc/locale.conf file
and set the default locale
localectl set-locale LANG="de_DE.UTF-8"
Then if I exit and log again, the oh-my-zsh will work fine.

Vim with R-plugin and LaTeX-Suite results in backslash in insert mode misbehaving

Here's what happens. I'm using Vim + LaTeX-Suite to edit TeX files in Vim. This could be in the Terminal or in MacVim.
I happily
Insert lots of $\LaTeX \commands$ etc. I love using the $\backslash$.
TeX works great. No problem.
Then I go and open up a .R file in the same window (different tab). R-Plugin for Vim uses the <Leader> key (mapped to \ as per usual) to execute commands, e.g. I type \sa to send the selection to R and execute and move the window down. Life is nice.
Problem: even though while editing an R file, Vim is nice enough not to bug me in insert mode when I type \, for some reason when I switch back to the tab to edit the TeX file, then type \ in insert mode, it moves the cursor left of the \ and pauses as though waiting for the rest of the command, before then re-moving to the right of the \ and moving on as I type.
Below shows what happens just from typing \ in insert mode; obviously I could reproduce this by moving the cursor to the left with the arrow keys, but that's not how this happened--the cursor just moves left for a split second as though waiting for the R command to finish being input.
So: how can I stop the annoying behavior in the TeX file insert mode, without sacrificing other functionality? Note, (a) I don't expect mapping <Leader> to a different key to help since then that key will just have the same left-cursor-move problem in TeX; (b), I like the leader as \ anyway so I don't want to change it.
Put this line in your vimrc (requires Vim-R-plugin >= 0.9.9.2):
let g:vimrplugin_insert_mode_cmds = 0
If the problem persists, you can do the following in Normal mode to know what are the keyboard shortcuts in Insert mode:
:imap

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