Read csv file from ADALM2000 Scopy and create Python Pandas DataFrame

read_scopy_csv.py

import pandas as pd

import datetime

def make_dt(timestr, start_dt):
    """
    Take starting datetime object and time stamp string in '23:20:35' format
    Return a datetime object with date info from starting datetime and time info from time stamp string    
    """
    ts = datetime.datetime.strptime(timestr, "%H:%M:%S")
    return datetime.datetime(start_dt.year, start_dt.month, start_dt.day, ts.hour, ts.minute, ts.second)

def add_day(td):
    """
    Measurement may happen overnight.
    Add a day if time delta is negative
    """
    while td.total_seconds() < 0:
        td += datetime.timedelta(hours=24)
    return td

def get_startdt_scopy_csv(fname):
    """
    Print out comment lines
    For log file from DMM, parse starting date&time and return DateTime object
    """
    startdt = None
    with open(fname) as f:
        for line in f.readlines():
            if line[0] == ";":
                print(line, end='')
                if line.startswith(";Started on "):
                    # log from DMM has a line with starting date&time
                    _, timestr = line.strip().split(";Started on ")
                    startdt = datetime.datetime.strptime(timestr, "%a %b %d %H:%M:%S %Y")
    return startdt
                    
def read_scopy_csv(fname):
    """
    Read csv file from Scopy and return as pandas.DataFrame
    Export from oscilloscope is just a simple reading
    Log from DMM adds a few columns
    """
    startdt = get_startdt_scopy_csv(fname)
    df = pd.read_csv(fname, comment=";")
    if startdt != None:
        # log file from DMM
        df.loc[:, 'datetime'] = df['Timestamp'].apply(make_dt, args=(startdt,))
        df.loc[:, 'timedelta'] = df['datetime'] - startdt
        df.loc[:, 'timedelta'] = df['timedelta'].apply(add_day)
        df.loc[:, 'elapsed time (s)'] = df['timedelta'].apply(lambda x: x.total_seconds())
    return df

if __name__ == "__main__":
    # Test log file from DMM
    fname = "scopy_dmm_log.csv"
    df = read_scopy_csv(fname)
    print(df.head())

    # Test export file from Oscilloscope
    fname = "scopy_oscilloscope_export.csv"
    df = read_scopy_csv(fname)
    print(df.head())