[BUG] Differences in Tyre Data after v3.6.0 compared with previous versions

[borolepratik]

Describe the issue:

After updated the lib to v3.6.0 I noticed that some data that was previously available (via v3.5.3) is now missing. I can be sure of this because I have charted the data from v3.5.3 and after updating to v3.6.0, some of it is missing. Also verified on a different computer which still has cache stored via v3.5.3.

Missing data - Tyre Compounds for a few drivers for a few laps in 2024 Emilia Romagna Grand Prix Practice 1 session.

Time | Driver | DriverNumber | LapTime | LapNumber | Stint | PitOutTime | PitInTime | Sector1Time | Sector2Time | Sector3Time | Sector1SessionTime | Sector2SessionTime | Sector3SessionTime | SpeedI1 | SpeedI2 | SpeedFL | SpeedST | IsPersonalBest | Compound | TyreLife | FreshTyre | Team | LapStartTime | LapStartDate | TrackStatus | Position | Deleted | DeletedReason | FastF1Generated | IsAccurate

0 days 00:24:15.195000 | SAR | 2 | NaT | 2.0 | 2.0 | 0 days 00:22:30.970000 | NaT | NaT | 0 days 00:00:33.336000 | 0 days 00:00:40.198000 | NaT | 0 days 00:23:35.278000 | 0 days 00:24:15.320000 | 177.0 | 236.0 | 272.0 | 155.0 | False | None | 2.0 | False | Williams | 0 days 00:14:50.921000 | 2024-05-17 11:32:00.988 | 1 | NaN | False |   | False | False
0 days 00:25:37.915000 | SAR | 2 | 0 days 00:01:22.720000 | 3.0 | 2.0 | NaT | NaT | 0 days 00:00:26.602000 | 0 days 00:00:28.383000 | 0 days 00:00:27.735000 | 0 days 00:24:41.797000 | 0 days 00:25:10.180000 | 0 days 00:25:37.915000 | 214.0 | 257.0 | 274.0 | 296.0 | True | None | 3.0 | False | Williams | 0 days 00:24:15.195000 | 2024-05-17 11:41:25.262 | 1 | NaN | False |   | False | True
0 days 00:27:30.729000 | SAR | 2 | 0 days 00:01:52.814000 | 4.0 | 2.0 | NaT | NaT | 0 days 00:00:34.372000 | 0 days 00:00:41.721000 | 0 days 00:00:36.721000 | 0 days 00:26:12.287000 | 0 days 00:26:54.008000 | 0 days 00:27:30.729000 | 156.0 | 175.0 | 271.0 | 168.0 | False | None | 4.0 | False | Williams | 0 days 00:25:37.915000 | 2024-05-17 11:42:47.982 | 1 | NaN | False |   | False | True
0 days 00:28:51.288000 | SAR | 2 | 0 days 00:01:20.559000 | 5.0 | 2.0 | NaT | NaT | 0 days 00:00:25.717000 | 0 days 00:00:27.968000 | 0 days 00:00:26.874000 | 0 days 00:27:56.446000 | 0 days 00:28:24.414000 | 0 days 00:28:51.288000 | 218.0 | 259.0 | 273.0 | 299.0 | True | None | 5.0 | False | Williams | 0 days 00:27:30.729000 | 2024-05-17 11:44:40.796 | 1 | NaN | False |   | False | True
0 days 00:30:47.639000 | SAR | 2 | 0 days 00:01:56.351000 | 6.0 | 2.0 | NaT | NaT | 0 days 00:00:40.372000 | 0 days 00:00:41.309000 | 0 days 00:00:34.670000 | 0 days 00:29:31.660000 | 0 days 00:30:12.969000 | 0 days 00:30:47.639000 | 144.0 | 209.0 | 276.0 | 242.0 | False | None | 6.0 | False | Williams | 0 days 00:28:51.288000 | 2024-05-17 11:46:01.355 | 1 | NaN | False |   | False | True
0 days 00:32:07.540000 | SAR | 2 | 0 days 00:01:19.901000 | 7.0 | 2.0 | NaT | NaT | 0 days 00:00:25.313000 | 0 days 00:00:27.808000 | 0 days 00:00:26.780000 | 0 days 00:31:12.952000 | 0 days 00:31:40.760000 | 0 days 00:32:07.540000 | 216.0 | 259.0 | 277.0 | 293.0 | True | None | 7.0 | False | Williams | 0 days 00:30:47.639000 | 2024-05-17 11:47:57.706 | 125 | NaN | False |   | False | False
0 days 00:47:08.352000 | SAR | 2 | NaT | 8.0 | 2.0 | NaT | 0 days 00:34:02.448000 | NaT | NaT | NaT | NaT | NaT | NaT | NaN | NaN | NaN | NaN | False | None | 8.0 | False | Williams | 0 days 00:32:07.540000 | 2024-05-17 11:49:17.607 | 51 | NaN | False |   | False | False
0 days 00:29:30.298000 | GAS | 10 | NaT | 2.0 | 2.0 | 0 days 00:27:55.685000 | NaT | NaT | 0 days 00:00:33.702000 | 0 days 00:00:30.666000 | NaT | 0 days 00:28:59.712000 | 0 days 00:29:30.298000 | 166.0 | 222.0 | 265.0 | 266.0 | False | None | 2.0 | False | Alpine | 0 days 00:15:42.011000 | 2024-05-17 11:32:52.078 | 1 | NaN | False |   | False | False
0 days 00:30:50.953000 | GAS | 10 | 0 days 00:01:20.655000 | 3.0 | 2.0 | NaT | NaT | 0 days 00:00:25.933000 | 0 days 00:00:27.851000 | 0 days 00:00:26.871000 | 0 days 00:29:56.231000 | 0 days 00:30:24.082000 | 0 days 00:30:50.953000 | 214.0 | 253.0 | 269.0 | 293.0 | True | None | 3.0 | False | Alpine | 0 days 00:29:30.298000 | 2024-05-17 11:46:40.365 | 1 | NaN | False |   | False | True
0 days 00:42:45.524000 | GAS | 10 | NaT | 4.0 | 2.0 | NaT | 0 days 00:32:54.605000 | 0 days 00:00:38.825000 | NaT | NaT | 0 days 00:31:29.841000 | NaT | NaT | 129.0 | NaN | NaN | NaN | False | None | 4.0 | False | Alpine | 0 days 00:30:50.953000 | 2024-05-17 11:48:01.020 | 125 | NaN | False |   | False | False
0 days 00:44:21.059000 | GAS | 10 | NaT | 5.0 | 3.0 | 0 days 00:42:45.524000 | NaT | NaT | 0 days 00:00:34.566000 | 0 days 00:00:29.854000 | NaT | 0 days 00:43:51.411000 | 0 days 00:44:21.264000 | 164.0 | 227.0 | 267.0 | 265.0 | False | None | 4.0 | False | Alpine | 0 days 00:42:45.524000 | 2024-05-17 11:59:55.591 | 1 | NaN | False |   | False | False
0 days 00:45:40.490000 | GAS | 10 | 0 days 00:01:19.431000 | 6.0 | 3.0 | NaT | NaT | 0 days 00:00:25.427000 | 0 days 00:00:27.347000 | 0 days 00:00:26.657000 | 0 days 00:44:46.486000 | 0 days 00:45:13.833000 | 0 days 00:45:40.490000 | 216.0 | 255.0 | 267.0 | 291.0 | True | None | 5.0 | False | Alpine | 0 days 00:44:21.059000 | 2024-05-17 12:01:31.126 | 1 | NaN | False |   | False | True
0 days 00:47:44.743000 | GAS | 10 | 0 days 00:02:04.253000 | 7.0 | 3.0 | NaT | NaT | 0 days 00:00:37.348000 | 0 days 00:00:52.505000 | 0 days 00:00:34.400000 | 0 days 00:46:17.838000 | 0 days 00:47:10.343000 | 0 days 00:47:44.743000 | 115.0 | 126.0 | 267.0 | 257.0 | False | None | 6.0 | False | Alpine | 0 days 00:45:40.490000 | 2024-05-17 12:02:50.557 | 1 | NaN | False |   | False | True
0 days 00:49:03.563000 | GAS | 10 | 0 days 00:01:18.820000 | 8.0 | 3.0 | NaT | NaT | 0 days 00:00:25 | 0 days 00:00:27.212000 | 0 days 00:00:26.608000 | 0 days 00:48:09.743000 | 0 days 00:48:36.955000 | 0 days 00:49:03.563000 | 223.0 | 255.0 | 271.0 | 294.0 | True | None | 7.0 | False | Alpine | 0 days 00:47:44.743000 | 2024-05-17 12:04:54.810 | 1 | NaN | False |   | False | True
0 days 00:51:12.627000 | GAS | 10 | 0 days 00:02:09.064000 | 9.0 | 3.0 | NaT | NaT | 0 days 00:00:43.035000 | 0 days 00:00:53.195000 | 0 days 00:00:32.834000 | 0 days 00:49:46.598000 | 0 days 00:50:39.793000 | 0 days 00:51:12.627000 | 109.0 | 185.0 | 266.0 | 242.0 | False | None | 8.0 | False | Alpine | 0 days 00:49:03.563000 | 2024-05-17 12:06:13.630 | 1 | NaN | False |   | False | True
0 days 00:52:31.371000 | GAS | 10 | 0 days 00:01:18.744000 | 10.0 | 3.0 | NaT | NaT | 0 days 00:00:24.913000 | 0 days 00:00:27.202000 | 0 days 00:00:26.629000 | 0 days 00:51:37.540000 | 0 days 00:52:04.742000 | 0 days 00:52:31.371000 | 224.0 | 256.0 | 267.0 | 292.0 | True | None | 9.0 | False | Alpine | 0 days 00:51:12.627000 | 2024-05-17 12:08:22.694 | 1 | NaN | False |   | False | True
0 days 00:54:18.561000 | GAS | 10 | 0 days 00:01:47.190000 | 11.0 | 3.0 | NaT | 0 days 00:54:14.143000 | 0 days 00:00:35.248000 | 0 days 00:00:36.585000 | 0 days 00:00:35.357000 | 0 days 00:53:06.619000 | 0 days 00:53:43.204000 | 0 days 00:54:18.561000 | 166.0 | 224.0 | NaN | 239.0 | False | None | 10.0 | False | Alpine | 0 days 00:52:31.371000 | 2024-05-17 12:09:41.438 | 1 | NaN | False |   | False | False
0 days 00:38:07.464000 | ALO | 14 | NaT | 3.0 | 2.0 | 0 days 00:31:29.240000 | 0 days 00:33:10.524000 | NaT | NaT | NaT | NaT | NaT | NaT | 208.0 | NaN | NaN | NaN | False | None | 3.0 | False | Aston Martin | 0 days 00:16:20.314000 | 2024-05-17 11:33:30.381 | 125 | NaN | False |   | False | False
0 days 00:39:30.964000 | ALO | 14 | NaT | 4.0 | 3.0 | 0 days 00:38:07.464000 | NaT | NaT | 0 days 00:00:28.550000 | 0 days 00:00:30.598000 | NaT | 0 days 00:39:00.575000 | 0 days 00:39:31.076000 | 211.0 | 246.0 | 269.0 | 284.0 | False | None | 3.0 | False | Aston Martin | 0 days 00:38:07.464000 | 2024-05-17 11:55:17.531 | 1 | NaN | False |   | False | False
0 days 00:40:51.192000 | ALO | 14 | 0 days 00:01:20.228000 | 5.0 | 3.0 | NaT | NaT | 0 days 00:00:25.264000 | 0 days 00:00:27.630000 | 0 days 00:00:27.334000 | 0 days 00:39:56.228000 | 0 days 00:40:23.858000 | 0 days 00:40:51.192000 | 224.0 | 258.0 | 269.0 | 296.0 | True | None | 4.0 | False | Aston Martin | 0 days 00:39:30.964000 | 2024-05-17 11:56:41.031 | 1 | NaN | False |   | False | True
0 days 00:42:23.577000 | ALO | 14 | 0 days 00:01:32.385000 | 6.0 | 3.0 | NaT | NaT | 0 days 00:00:28.310000 | 0 days 00:00:30.768000 | 0 days 00:00:33.307000 | 0 days 00:41:19.502000 | 0 days 00:41:50.270000 | 0 days 00:42:23.577000 | 199.0 | 240.0 | 272.0 | 244.0 | False | None | 5.0 | False | Aston Martin | 0 days 00:40:51.192000 | 2024-05-17 11:58:01.259 | 1 | NaN | False |   | False | True
0 days 00:43:43.228000 | ALO | 14 | 0 days 00:01:19.651000 | 7.0 | 3.0 | NaT | NaT | 0 days 00:00:24.939000 | 0 days 00:00:27.589000 | 0 days 00:00:27.123000 | 0 days 00:42:48.516000 | 0 days 00:43:16.105000 | 0 days 00:43:43.228000 | 222.0 | 260.0 | 273.0 | 298.0 | True | None | 6.0 | False | Aston Martin | 0 days 00:42:23.577000 | 2024-05-17 11:59:33.644 | 1 | NaN | False |   | False | True
0 days 00:45:34.709000 | ALO | 14 | 0 days 00:01:51.481000 | 8.0 | 3.0 | NaT | NaT | 0 days 00:00:37.408000 | 0 days 00:00:38.204000 | 0 days 00:00:35.869000 | 0 days 00:44:20.636000 | 0 days 00:44:58.840000 | 0 days 00:45:34.709000 | 189.0 | 226.0 | 272.0 | 261.0 | False | None | 7.0 | False | Aston Martin | 0 days 00:43:43.228000 | 2024-05-17 12:00:53.295 | 1 | NaN | False |   | False | True
0 days 00:46:53.671000 | ALO | 14 | 0 days 00:01:18.962000 | 9.0 | 3.0 | NaT | NaT | 0 days 00:00:24.758000 | 0 days 00:00:27.409000 | 0 days 00:00:26.795000 | 0 days 00:45:59.467000 | 0 days 00:46:26.876000 | 0 days 00:46:53.671000 | 226.0 | 259.0 | 271.0 | 295.0 | True | None | 8.0 | False | Aston Martin | 0 days 00:45:34.709000 | 2024-05-17 12:02:44.776 | 1 | NaN | False |   | False | True
0 days 00:48:41.615000 | ALO | 14 | 0 days 00:01:47.944000 | 10.0 | 3.0 | NaT | NaT | 0 days 00:00:36.074000 | 0 days 00:00:35.483000 | 0 days 00:00:36.387000 | 0 days 00:47:29.745000 | 0 days 00:48:05.228000 | 0 days 00:48:41.615000 | 187.0 | 230.0 | 276.0 | 111.0 | False | None | 9.0 | False | Aston Martin | 0 days 00:46:53.671000 | 2024-05-17 12:04:03.738 | 1 | NaN | False |   | False | True
0 days 00:50:01.063000 | ALO | 14 | 0 days 00:01:19.448000 | 11.0 | 3.0 | NaT | NaT | 0 days 00:00:24.679000 | 0 days 00:00:27.422000 | 0 days 00:00:27.347000 | 0 days 00:49:06.294000 | 0 days 00:49:33.716000 | 0 days 00:50:01.063000 | 221.0 | 260.0 | 264.0 | 300.0 | False | None | 10.0 | False | Aston Martin | 0 days 00:48:41.615000 | 2024-05-17 12:05:51.682 | 1 | NaN | False |   | False | True
0 days 00:51:31.453000 | ALO | 14 | 0 days 00:01:30.390000 | 12.0 | 3.0 | NaT | 0 days 00:51:27.748000 | 0 days 00:00:27.121000 | 0 days 00:00:29.257000 | 0 days 00:00:34.012000 | 0 days 00:50:28.184000 | 0 days 00:50:57.441000 | 0 days 00:51:31.453000 | 213.0 | 243.0 | NaN | 287.0 | False | None | 11.0 | False | Aston Martin | 0 days 00:50:01.063000 | 2024-05-17 12:07:11.130 | 1 | NaN | False |   | False | False
0 days 00:29:01.307000 | ZHO | 24 | NaT | 3.0 | 2.0 | 0 days 00:27:23.086000 | NaT | NaT | 0 days 00:00:35.887000 | 0 days 00:00:33.913000 | NaT | 0 days 00:28:27.603000 | 0 days 00:29:01.368000 | 199.0 | 239.0 | 267.0 | 251.0 | False | None | 3.0 | False | Kick Sauber | 0 days 00:16:53.917000 | 2024-05-17 11:34:03.984 | 1 | NaN | False |   | False | False
0 days 00:30:22.946000 | ZHO | 24 | 0 days 00:01:21.639000 | 4.0 | 2.0 | NaT | NaT | 0 days 00:00:26.286000 | 0 days 00:00:28.171000 | 0 days 00:00:27.182000 | 0 days 00:29:27.593000 | 0 days 00:29:55.764000 | 0 days 00:30:22.946000 | 220.0 | 256.0 | 269.0 | 295.0 | True | None | 4.0 | False | Kick Sauber | 0 days 00:29:01.307000 | 2024-05-17 11:46:11.374 | 1 | NaN | False |   | False | True
0 days 00:55:51.308000 | ZHO | 24 | NaT | 5.0 | 2.0 | NaT | 0 days 00:32:22.452000 | 0 days 00:00:40.741000 | 0 days 00:00:42.423000 | NaT | 0 days 00:31:03.884000 | 0 days 00:31:46.268000 | NaT | 150.0 | 222.0 | NaN | 215.0 | False | None | 5.0 | False | Kick Sauber | 0 days 00:30:22.946000 | 2024-05-17 11:47:33.013 | 125 | NaN | False |   | False | False

Reproduce the code example:

import fastf1

# Parameters
year = 2024
grand_prix = 7
session = 1

# Load session data
session = fastf1.get_session(year, grand_prix, session)
session.load()

laps = session.laps
valid_compounds = ['SOFT', 'MEDIUM', 'HARD', 'INTERMEDIATE', 'WET']
laps[~laps['Compound'].isin(valid_compounds)]

Error message:

[borolepratik]

Running the repro code with cache from v3.5.3 does not produce any output.

[theOehrly]

I will look into this. Did you find this one session by chance, or did you somehow test a lot of sessions for changes after the update?

[borolepratik]

Have found this one instance and only in 2024. I will be looking at other years shortly (heavily restricted by Jolpica rate limits).

[theOehrly]

A very quick look at just one difference in that session showed that car number 2 (SAR) drove four stints with the following tyres

• previously: Medium, Medium, Soft, Medium
• now: Medium, None, Soft, Medium

But looking at the raw source data, there actually is no correct compound information for the second stint of car number 2. That a Medium compound was previously listed for this stint is incorrect. The data as it is now is correct.

Less data does not necessarily mean that the data is less correct. It seems that those missing values were just previously masked by the bug that has now been fixed.

I will have a closer look at this session when I have the time, but for now I am happy.

[borolepratik]

If what we have right now is more accurate data, then i'm okay with it. I'd prefer accurate data over completeness.

[Zalberth]

For some reason, I found 2025 Hungary ALO laps' data is not complete, filtering by driver_laps = driver_laps[~driver_laps['SpeedST'].isna()] , the len(driver_laps) only outputs 41。29 laps do not contains Speed Trap data.

[theOehrly]

For some reason, I found 2025 Hungary ALO laps' data is not complete, filtering by driver_laps = driver_laps[~driver_laps['SpeedST'].isna()] , the len(driver_laps) only outputs 41。29 laps do not contains Speed Trap data.

Please do not reuse unrelated issues. This is not something that is new in v3.6.0.

The problem is also not specific to Alonso in this race, but that is less important. The missing values are most likely equivalent to the value from the previous lap. I will investigate this a bit more and likely fix it in an upcoming release.