Autosuggestion is a very useful feature available in [fish](https://fishshell.com/), [zsh](https://en.wikipedia.org/wiki/Z_shell), and [prompt-toolkit](https://python-prompt-toolkit.readthedocs.io/en/master/pages/asking_for_input.html#auto-suggestion).

[Ptpython](https://github.com/prompt-toolkit/ptpython#ptpython) allows users to enable this feature in
[ptpython/config.py](https://github.com/prompt-toolkit/ptpython/blob/master/examples/ptpython_config/config.py#L90>).

This feature allows users to accept autosuggestions with ctrl e, ctrl f, or right arrow as described below.

1. Start ipython

![image](https://user-images.githubusercontent.com/13444106/94700432-76580100-0309-11eb-8798-040d47d1a540.png)

2. Run `print("hello")`

![image](https://user-images.githubusercontent.com/13444106/94700528-91c30c00-0309-11eb-920d-4ef8aa79d79a.png)

3. Press p to see the autosuggestion

![image](https://user-images.githubusercontent.com/13444106/94700681-bf0fba00-0309-11eb-94bd-bbddf4805da2.png)

4. Press ctrl f, or ctrl e, or right arrow to accept the suggestion

![image](https://user-images.githubusercontent.com/13444106/94700883-fd0cde00-0309-11eb-9aa8-17270951f021.png)

You can also complete word by word:

1. Run `def say_hello(): print("hello")`

![image](https://user-images.githubusercontent.com/13444106/94704474-f54f3880-030d-11eb-9d73-fa10ced850be.png)

2. Press d to see the autosuggestion

![image](https://user-images.githubusercontent.com/13444106/94704519-fe400a00-030d-11eb-8b73-3c35ffaf1a9d.png)

3. Press alt f to accept to accept the first word of the suggestion

![image](https://user-images.githubusercontent.com/13444106/94704602-14e66100-030e-11eb-90fc-d930463f52de.png)

Importantly, this feature does not interfere with tab completion:

1. After running `def say_hello(): print("hello")`, press d

![image](https://user-images.githubusercontent.com/13444106/94704519-fe400a00-030d-11eb-8b73-3c35ffaf1a9d.png)

2. Press Tab to start tab completion

![image](https://user-images.githubusercontent.com/13444106/94704969-80303300-030e-11eb-8379-6bff94582849.png)

3A. Press Tab again to select the first option

![image](https://user-images.githubusercontent.com/13444106/94705023-90481280-030e-11eb-9cf7-76170d1004b9.png)

3B. Press alt f to accept to accept the first word of the suggestion

![image](https://user-images.githubusercontent.com/13444106/94704602-14e66100-030e-11eb-90fc-d930463f52de.png)

3C. Press ctrl f or ctrl e to accept the entire suggestion

![image](https://user-images.githubusercontent.com/13444106/94705115-ab1a8700-030e-11eb-9dee-da98fccca0a6.png)

To install a version of ipython with autosuggestions enabled, run:

`pip install git+https://github.com/mskar/ipython@auto_suggest`

Currently, autosuggestions are only shown in the emacs or vi insert editing modes:
- The ctrl e, ctrl f, and alt f shortcuts work by default in emacs mode.
- To use these shortcuts in vi insert mode, you will have to create [custom keybindings in your config.py](https://github.com/mskar/setup/commit/2892fcee46f9f80ef7788f0749edc99daccc52f4/).