Unwanted newlines being added to output.

[epage]

I want to group my tables:

[first]
foo = 5
bar = 20
[first.a.b.c]
alice = 10
bob = 30

[second]       
foo = 3
bar = 21
[second.a.b.c]
alice = 15
bob = 3543

When I try to manually construct this, I instead get

[first]
foo = 5
bar = 20

[first.a.b.c]
alice = 10
bob = 30


[second]       
foo = 3
bar = 21

[second.a.b.c]
alice = 15
bob = 3543

I expected no newlines to be added for me and explicitly called out a newline between [first.a.b.c] table and [second]. Newlines being added surprised me and made made me wonder if tomlkit was properly preserving the lack of newlines but it seems to.

So I created the following test case to experiment with how newlines are dealt with

import tomlkit

t = tomlkit.loads("""[first]
foo = 5
bar = 20
[first.a.b.c]
alice = 10
bob = 30
[second]
foo = 3
bar = 21
[second.a.b.c]
alice = 15
bob = 3543""")

print("Round-trip")
print("```toml")
print(tomlkit.dumps(t))
print("```")
print()

t["second"].add("extra", tomlkit.table())
t["second"].add("extra1", tomlkit.table())
three = tomlkit.table()
three["foo"] = 2
three["bar"] = 1
child = tomlkit.table()
child["alice"] = 3
child["bob"] = 10
three["child"] = child
t["three"] = three


print("Changed")
print("```toml")
print(tomlkit.dumps(t))
print("```")
print()

The output is:
Round-trip

[first]
foo = 5
bar = 20
[first.a.b.c]
alice = 10
bob = 30
[second]
foo = 3
bar = 21
[second.a.b.c]
alice = 15
bob = 3543

Changed

[first]
foo = 5
bar = 20
[first.a.b.c]
alice = 10
bob = 30
[second]
foo = 3
bar = 21
[second.a.b.c]
alice = 15
bob = 3543
[second.extra]

[second.extra1]

[three]
foo = 2
bar = 1

[three.child]
alice = 3
bob = 10

I was surprised that second.extra didn't have a newline before it but second.extra1 did. I imagine this just shows how the newlines are being auto-added but it is still surprising.

[epage]

My ideal would be for no extra newlines to be added but it'd be nice if the API was clarified to at least help someone know how to prevent this from happening.

[ofek]

I handle this with:

if new_config.__class__.__name__ == 'Table':
    table_body = getattr(new_config.value, 'body', [])
    possible_whitespace = table_body[-2:]
    if len(possible_whitespace) == 2:
        for key, item in possible_whitespace:
            if key is not None:
                break
            if item.__class__.__name__ != 'Whitespace':
                break
        else:
            del table_body[-2]

[hockeybuggy]

I think this might be a product of this conditional here?: https://github.com/sdispater/tomlkit/blob/2c4dc76d23c242de1eb4bb725209895287fc5acc/tomlkit/container.py#L644-L646

[voronind]

Annoying bug

[ofek]

I can no longer reproduce this bug on the latest minor series.