Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

ReaderType.LAST does not return last value

Open
#388 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
data

Research direction

Start by reproducing the example with ReaderType.LAST and 'SNAPSHOT', then trace the c.read() handling for those read types and compare it with the ACTUAL result. Verify that the returned timestamp is the latest available data point rather than the earlier value shown in the report.

Written by the indexing model from the issue text.

Description

When using ReaderType.ACTUAL or 'SNAPSHOT', the last value retrieved consistently shows an hour offset. Instead of retrieving the actual last data point, it returns the data point from one hour earlier.

This code:

  import tagreader
  from tagreader import list_sources
  from datetime import datetime, timedelta
  from tagreader.utils import ReaderType
  
  c = tagreader.IMSClient(datasource='GFC', imstype='aspenone')
  try:
      c.connect()
      print("Connection successful")
  except Exception as e:
      print(f"Connection failed: {e}")
  
  
  # Use the read() method to read the tag data
  df_LAST = c.read(tags=['GFC.03-ST121.RPM'], read_type=ReaderType.LAST)
  df_SNAPSHOT = c.read(tags=['GFC.03-ST121.RPM'], read_type='SNAPSHOT')
  df = c.read(tags=['GFC.03-ST121.RPM'], start_time='04-11-24 12:50:00', end_time='04-11-24 13:10:00', read_type=ReaderType.ACTUAL)
  
  # Print the result
  print(df_LAST)
  print(df_SNAPSHOT)
  print(df)

returns:

  Connection successful
                             GFC.03-ST121.RPM
  time
  2024-11-04 12:05:41+01:00        8988.56543
                             GFC.03-ST121.RPM
  time
  2024-11-04 12:05:41+01:00        8988.56543
                                    GFC.03-ST121.RPM
  time
  2024-11-04 12:50:12.501000+01:00       8978.452148
  2024-11-04 12:50:53.505000+01:00       8989.392578
  2024-11-04 12:51:03.513000+01:00       9000.988281
  2024-11-04 12:51:13.511000+01:00       9011.892578
  2024-11-04 12:51:33.513000+01:00       9022.156250
  2024-11-04 12:52:27.522000+01:00       9011.138672
  2024-11-04 12:52:36.523000+01:00       9000.280273
  2024-11-04 12:52:45.524000+01:00       9010.517578
  2024-11-04 12:53:15.531000+01:00       9021.043945
  2024-11-04 12:53:24.532000+01:00       9032.085938
  2024-11-04 12:53:29.532000+01:00       9021.666992
  2024-11-04 12:53:33.533000+01:00       9031.952148
  2024-11-04 12:53:53.535000+01:00       9042.305664
  2024-11-04 12:53:57.535000+01:00       9032.219727
  2024-11-04 12:54:12.541000+01:00       9042.305664
  2024-11-04 12:54:20.542000+01:00       9031.284180
  2024-11-04 12:55:12.551000+01:00       9042.038086
  2024-11-04 12:56:31.563000+01:00       9053.131836
  2024-11-04 12:57:19.571000+01:00       9042.886719
  2024-11-04 12:57:45.574000+01:00       9032.442383
  2024-11-04 12:58:31.583000+01:00       9021.310547

where the data point: 2024-11-04 12:58:31.583000+01:00 9021.310547 is the actual last datapoint.

Dominant language
Python
Stars
55
Forks
21
Avg merge
11d 9h
Merged PRs (30d)
2

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from equinor/tagreader-python

All issues in equinor/tagreader-python

Similar issues

More Python issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.