P and Q are not keys of itch.h5

thanks for your work, it is very wonderfull !
In this file 02_market_and_fundamental_data/01_parse_itch_order_flow_messages
I want to know why in fle “01_parse_itch_order_flow_messages”, you store message all 2.5e7 message_count (see if message_count % 2.5e7 == 0:) ?

I ask you that because i have a error store['P'] and store['Q'] does not exists in this line :

`trades = store['P'].append(store['Q'].rename(columns={'cross_price': 'price'}), sort=False).merge(stocks)`

If i launch this file in python, i have this error :

Traceback (most recent call last):
  File "/usr/src/app/./01_parse_itch_order_flow_messages.py", line 531, in <module>
    trades = store['P'].append(store['Q'].rename(columns={'cross_price': 'price'}), sort=False).merge(stocks)
  File "/usr/local/lib/python3.12/site-packages/pandas/io/pytables.py", line 601, in __getitem__
    return self.get(key)
  File "/usr/local/lib/python3.12/site-packages/pandas/io/pytables.py", line 811, in get
    raise KeyError(f"No object named {key} in the file")
KeyError: 'No object named P in the file'


Similar question here

I found a solution, see here Error in Chapter 2 Code - #7 by JB31