Convert a timestamp to epoch timestamp int in milliseconds

get_epoch.py

from datetime import datetime
from dateutil import parser

def get_epoch(timestamp):
    """
    Convert a timestamp to epoch timestamp int in milliseconds
    Accepts timestamp in seconds or milliscons as a float OR an int, or a datetime-coercible string
    Raises ValueError if the timestamp is not valid
    """
    try:
        # Attempt to convert to float; works for int, float, or floatable string.
        timestamp_float = float(timestamp)
    except (ValueError, TypeError) as e:
        # if timestamp is not convertible to float and it's a string, try to coerce it to epoch time in milliseconds
        if isinstance(timestamp, str):
            try:
                dt = parser.parse(timestamp)
                print(f"datetime (parsed): {dt}")
                epoch_sec = dt.timestamp()
                # convert seconds to milliseconds
                return int(epoch_sec * 1000)
            except Exception as e:
                raise ValueError(f"Dateutil parser could not parse '{timestamp}': {e}")
        else:
            raise ValueError(f"Timestamp '{timestamp}' is not convertible to float: {e}")

    # timestamp is float-able, check if it's valid datetime
    try:
        # Validate timestamp is seconds
        dt = datetime.fromtimestamp(timestamp_float)
        print(f"datetime (seconds): {dt}")
        # convert seconds to milliseconds
        return int(timestamp_float * 1000)
    # Note: datetime.fromtimestamp() raises OSError for out-of-range values on some systems.
    except (TypeError, ValueError, OSError) as e:
        # Validate timestamp is milliseconds
        try:
            dt = datetime.fromtimestamp(timestamp_float / 1000)
            # timestamp is valid, already milliseconds
            print(f"datetime (milliseconds): {dt}")
            return int(timestamp_float)
        # Note: datetime.fromtimestamp() raises OSError for out-of-range values on some systems.
        except (TypeError, ValueError, OSError) as e:
            raise ValueError(f"'{timestamp_float}' is not a valid timestamp: {e}")


# Various date-time string formats
date_strings = [
    "2025-05-30 08:48:56",
    "1748594936000",
    1748594936,
]

for date in date_strings:
    try:
        print(get_epoch(date))
    except ValueError as e:
        print(f"Could not parse '{date}': {e}")

# All print:
# datetime (parsed): 2025-05-30 08:48:56
# 1748594936000