ValueError: time data 'LEGACY SYSTEM' does not match format '%H:%M:%S'

Question

I see this is a popular question, so hopefully someone can help me out. I, however, am stumped. I have CSV file that contains a timestamp in the first column, such as

18:49:45
19:50:31
20:51:26

My code is below. I think I am using the proper formatting for 24-hours, minutes, and seconds.

  import csv
  import time

  with open('file.csv', 'rb')as csvfile:
      filereader = csv.reader(csvfile, delimiter=',')
      for row in filereader:
          date = row[0]
          parsed = datetime.datetime.strptime(date, '%H:%M:%S')

Error: ValueError: time data 'LEGACY SYSTEM' does not match format '%H:%M:%S'

Answer 1

You have a header row. You can use next to retrieve (and then discard) the first line from your csv.reader iterator:

from datetime import datetime
import csv
from io import StringIO

file = StringIO("""LEGACY SYSTEM
18:49:45
19:50:31
20:51:26""")

# replace file with open('file.csv', 'rb')
with file as csvfile:
    filereader = csv.reader(csvfile, delimiter=',')
    next(filereader)
    for row in filereader:
        parsed = datetime.strptime(row[0], '%H:%M:%S')
        print(parsed)

# 1900-01-01 18:49:45
# 1900-01-01 19:50:31
# 1900-01-01 20:51:26

If you have multiple, say two, header rows, you can use a for loop to ignore them:

for _ in range(2):
    next(filereader)