Cotton Continuation contracts pulling CRT_MNTH and EXPIR_DATE

Hi,

I have code below

http://import lseg.data as ld
import pandas as pd
import time
from datetime import datetime, timedelta
from dateutil.relativedelta import relativedelta

# ------------------------------------------------------------------------------
# 1. Open LSEG Data session
# ------------------------------------------------------------------------------
print("Opening LSEG Data session...")
ld.open_session()
print("Session opened.\n")

# ------------------------------------------------------------------------------
# 2. Define RICs and requested fields
# ------------------------------------------------------------------------------
continuation_rics = [
    "CTc1", "CTc2", "CTc3", "CTc4", "CTc5",
    "CTc6", "CTc7", "CTc8", "CTc9", "CTc10"
]

requested_fields = [

]

# ------------------------------------------------------------------------------
# 3. Define date range and chunking logic
# ------------------------------------------------------------------------------
start_date_str = "2000-01-01"
end_date_str   = "2024-03-02"
start_date = datetime.strptime(start_date_str, "%Y-%m-%d")
end_date   = datetime.strptime(end_date_str, "%Y-%m-%d")

print(f"Date range set from {start_date_str} to {end_date_str}.\n")

chunk_years = 1  # Chunk size: 1 year at a time
current_start = start_date
all_chunks = []

# ------------------------------------------------------------------------------
# 4. Fetch data in chunks and log timing
# ------------------------------------------------------------------------------
while current_start <= end_date:
    # Determine chunk end (inclusive)
    chunk_end = current_start + relativedelta(years=chunk_years) - timedelta(days=1)
    if chunk_end > end_date:
        chunk_end = end_date
    chunk_start_str = current_start.strftime("%Y-%m-%d")
    chunk_end_str   = chunk_end.strftime("%Y-%m-%d")
    
    print(f"Fetching data from {chunk_start_str} to {chunk_end_str}...")
    chunk_start_time = time.time()
    
    df_chunk = ld.get_history(
        continuation_rics,
        requested_fields,
        start=chunk_start_str,
        end=chunk_end_str,
        interval="1d"  # Assuming daily data intervals; adjust if needed.
    )
    
    chunk_end_time = time.time()
    print(f"Chunk fetched in {chunk_end_time - chunk_start_time:.2f} seconds.\n")
    
    if df_chunk is not None and not df_chunk.empty:
        all_chunks.append(df_chunk)
    else:
        print("No data returned for this chunk.")
    
    # Move to the next chunk (day after the current chunk_end)
    current_start = chunk_end + timedelta(days=1)

# ------------------------------------------------------------------------------
# 5. Combine the chunks and flatten multi-index columns if necessary
# ------------------------------------------------------------------------------
if all_chunks:
    full_df = pd.concat(all_chunks)
    full_df.drop_duplicates(inplace=True)
    print(f"Combined data shape after concatenating chunks: {full_df.shape}")
else:
    full_df = pd.DataFrame()
    print("No data retrieved from any chunks.")

if full_df.empty:
    print("No data in the final DataFrame. Exiting.")
else:
    # If the DataFrame has multi-index columns, flatten them
    if isinstance(full_df.columns, pd.MultiIndex):
        full_df.columns = [
            f"{col[0]}_{col[1]}" if col[1] else str(col[0])
            for col in full_df.columns
        ]
        print("Flattened multi-index columns.\n")

    # ------------------------------------------------------------------------------
    # 6. Log missing fields for specific instruments (CTc3 to CTc10)
    # ------------------------------------------------------------------------------
    # Check for each instrument whether CRT_MNTH and EXPIR_DATE are present.
    missing_info_instruments = []
    for ric in continuation_rics:
        col_crt = f"CRT_MNTH_{ric}"
        col_exp = f"EXPIR_DATE_{ric}"
        if col_crt not in full_df.columns or col_exp not in full_df.columns:
            missing_info_instruments.append(ric)
    
    if missing_info_instruments:
        print("Note: The following instruments did not return data for CRT_MNTH and/or EXPIR_DATE:")
        print(missing_info_instruments)
    else:
        print("All instruments returned CRT_MNTH and EXPIR_DATE data.\n")

My issue is that some data such as CRT_MNTH and EXPIR_DATE is failing to come in prior to about 2022 for all Continous contracts before 2022, what do I need to change in the code?

Could please provide the fix?