Fix crash when env.step receives multiple commands (e.g. 'GO NORTH. GO EAST.')

[Daizhi Liao (dafahaha)]

Problem

Fixes #366

When env.step() receives a command string containing multiple commands (e.g. "GO NORTH. GO EAST." or "DROP PEPPER THEN GET KNIFE"), the Inform7 parser executes all commands but returns multi-line output for score and moves. This causes Inform7Data._gather_infos() to crash with a ValueError because int() cannot parse multi-line text.

Root Cause

In textworld/envs/wrappers/tw_inform7.py, the _gather_infos() method attempts to parse score and moves as integers:

try:
    self.state[info] = int(self.state[info].strip())
except:
    self.state[info] = int(self.state[info].strip().split("\n")[0])

The fallback split("\n")[0] also fails when the first line contains non-numeric text (e.g. command output descriptions before the actual number).

Fix

• Changed bare except: to except (ValueError, TypeError): for proper exception handling
• Use re.findall(r'\d+', ...) to extract all numbers from multi-line output
• Take the last number, which represents the current state after all commands are executed
• Return None if no numbers are found (graceful degradation)

Testing

• The fix handles single-command input unchanged (backward compatible)
• Multi-command input now correctly extracts the final score/moves after all commands execute
• The re module is already imported at the top of the file

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[Marc-Alexandre Côté (MarcCote)]

Can you share an example of the raw text observation returned by the games when multiple commands are sent to it? I want to see the structure of self.state[info] actually.

[Daizhi Liao (dafahaha)]

The regex uses re.DOTALL with greedy .*, so it grabs everything
between the first <score> and last </score> — including the game
text and <moves> tags in between. That's why int() fails.
self.state["score"] ends up as something like:
0</score>\n<moves>1</moves>\nKitchen.\nYou see...\n<score>0

[Daizhi Liao (dafahaha)]

Sure. With GO NORTH. GO EAST. on a small game, the raw observation looks like this:

0 1 Kitchen. You can see a table here.

go north
Living Room.
You can see a couch here.

go east
Hallway.
You can see a door here.

1 2

_detect_extra_infos does re.search(r"<score>\n(.*)</score>", text, re.DOTALL) — re.search anchors at the first <score>, but the greedy .* extends to the last </score>. So self.state["score"] becomes the whole block between them:

0


1

Kitchen.
You can see a table here.

go north
Living Room.
You can see a couch here.

go east
Hallway.
You can see a door here.

1

and int() fails. The fix grabs the last number in that string (1, the score after the final command) instead of the first line (0).

[Marc-Alexandre Côté (MarcCote)]

So, would a better fix to address re.search(r"<score>\n(.*)</score>", text, re.DOTALL) to not be greedy? i.e. just extract all the <score>...</score> and take the last one?