Stacking

Example

An example of a Hit List

offset	column
1000	2
2000	3
4000	1

An example of a Hold List

offset	column	length
1000	3	100
2000	2	200
3500	3	500

An example of a Bpm List

offset	bpm	metronome
1000	200	4

If we stacked them, we yield::

offset	column	length	bpm	metronome
1000	3	100
2000	2	200
3500	3	500
1000	2
2000	3
4000	1
1000			200	4

This allows us to modify all matching properties at one go.

Here's how to use stack to add offset to everything.

from reamber.osu.OsuMap import OsuMap
m = OsuMap.read_file(...)
s = m.stack()
s.offset += 100

from reamber.quaver.QuaMap import QuaMap
m = QuaMap.read_file(...)
s = m.stack()
s.offset += 100

from reamber.bms import BMSMap
m = BMSMap.read_file(...)
s = m.stack()
s.offset += 100

from reamber.sm import SMMapSet
ms = SMMapSet.read_file(...)
s = ms.stack()
s.offset += 100

from reamber.o2jam import O2JMapSet
ms = O2JMapSet.read_file(...)
s = ms.stack()
s.offset += 100

Including

If you only wanted to change hits column only, you can pass it as an argument

from reamber.osu import OsuMap
from reamber.osu.lists.notes import OsuHitList

m = OsuMap.read_file("my_map.osu")
s = m.stack([OsuHitList])

Conditional Stacking

Condition Stacking only works on Map, not Mapset, see below for workaround

If you're familiar with pd.DataFrame, you can do something like

import pandas as pd

df = pd.DataFrame(...)
df.loc[df.offset < 1000, 'column'] += 1

This adds column by 1 where df.offset is less than 1000.

For stacking, you MUST also do it through loc.

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
stack.loc[stack.offset < 1000, 'column'] += 1

Do not do it through the property.

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
# Don't do this
stack.column[stack.offset < 1000] += 1

This raises a SettingWithCopy warning! This means, it might not have updated the stack by reference.

MapSet Stacking Caveats

When stacking with MapSet s, it will return a pd.DataFrame of the Map stack results. Due to copying caveats, conditional stacking will not work, loop through the maps and set individually.

from reamber.sm import SMMapSet

ms = SMMapSet.read_file("...")
stack = ms.stack()
stack.offset *= 2

If you want conditional stacking, loop and loc.

from reamber.sm import SMMapSet

ms = SMMapSet.read_file("...")
for m in ms:
    s = m.stack()
    s.loc[s.offset > 1000, 'column'] += 2

More Examples

To get acquainted with this, here are some additional examples. Learning this will be equivalent to learning pd.DataFrame conditional slicing and setting.

We assume stack = m.stack(), where m is a map if not specified.

First and Last Offsets

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
first, last = stack.offset.min(), (stack.offset + stack.length).max()

Note that indexing will yield a pd.Series.

Reversing Columns

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
keys = stack.column.max()
stack.column *= -1
stack.column += keys

Getting Columns Conditionally by Offset

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
cols = stack.loc[stack.offset >= 10000, 'column']

Multiple Conditions

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
stack.loc[(stack.column == 2) & (stack.offset > 1000), 'column']

Multiple Properties

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
stack.loc[(stack.column == 2) &
          (stack.offset > 1000), ['column', 'offset']] *= 2

SettingWithCopy Warning

If you're running into this issue, see above.

In short, when we write

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
stack.column[stack.offset < 1000] += 1

It expands to

from reamber.osu import OsuMap

stack = OsuMap.read_file("...").stack()
stack_copy = stack.__getitem__('column')
stack_copy[stack.offset < 1000] += 1

Notice that stack_copy may or may not be a copy, thus, it may not update the stack.

Last modified: 23 March 2024