neovim auto-indentation nuances - vim

Question

I've just switched from vim to neovim. The following vim config settings get the behaviour I want from indentation:
set tabstop=4
set shiftwidth=4
set softtabstop=4
set autoindent
set backspace=indent,eol,start
The relevant part here is the autoindent:
set autoindent
On each newline, this causes vim to match the indentation of the previous line:
def demo_autoindent():
a = 'This line was manually indented'
····
The declaration of a was manually indented one step, but the second line was auto-indented to the same level. Here I have represented the auto-indent with a series of · characters.
Neovim matches this behaviour. However, Neovim tries to be a bit clever with blocks, or in this case declaring dictionaries in python:
def example_neovim():
b = {
············
Note that Neovim has not auto-indented this line. If it had, it would have the same 4-space indent as the declaration of b. Instead, Neovim has added an extra two indents, bringing the total to 12-spaces.
Clearly what it intends to do is add one further indent:
def example_neovim_intention():
c = {
········
How do I configure Neovim to either:
Match the behaviour of vim, just auto-indent to the same level.
Add a single (rather than a double) extra indent when declaring e.g. a dict.

Answer 1

I was facing exactly the same issue, I used VIM for quite a long time and recently I switch to NeoVim.
Auto indention on for every other languages except "python" works well. I found this document quite useful: https://neovim.io/doc/user/indent.html#ft-python-indent .
:h ft-python-indent
NeoVim will check this variable g:python_indent, if it is not defined a default one will be created, and it would be something like this (NeoVim 0.8.2):
{
'disable_parentheses_indenting': v:false,
'closed_paren_align_last_line': v:true,
'searchpair_timeout': 150,
'continue': 'shiftwidth() * 2',
'open_paren': 'shiftwidth() * 2',
'nested_paren': 'shiftwidth()'
}
Change these properties continue,open_paren and closed_paren_align_last_line as follows.
{
'disable_parentheses_indenting': v:false,
'closed_paren_align_last_line': v:false,
'searchpair_timeout': 150,
'continue': 'shiftwidth()',
'open_paren': 'shiftwidth()',
'nested_paren': 'shiftwidth()'
}
Another Approach (Recommended)
This can fix the weird indention issue easier.
Setup nvim-treesitter/nvim-treesitter and turn on tree-sitter's indention feature.
require('nvim-treesitter/nvim-treesitter').setup {
...
indent = { enable = true },
...
}

Answer 2

The issue was that neovim has filetype-indentation enabled by default:
:filetype
filetype detection:ON plugin:ON indent:ON
Adding the following to my neovim init restored the basic auto-indent functionality:
filetype indent off
This is unsatisfactory. I suspect that the file-type detection is conflicting (or doubling) some other indent config that I have, but I haven't missed it since disabling it.