How to check if a column's value is in a list of candiates?

[oystesla]

When using filter, for a specific column, I want to check if the current value is not just one specific value, but whether it's present in a list of strings for example. I get deferred errors because the truth value hasn't been instantiated yet, unlike if I compare to a constant. I've tried find_in_set as well, but I get a SignatureValidationError?

What is the best approach here? I want to mirror what KQL is doing with this.

[gforsyth]

Hey @oystesla !

You're looking for the isin method on the column in question -- you can pass that a list of options and if the column value matches any of them, then it will return True

[ins] In [8]: t
Out[8]: 
┏━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┳━━━┓
┃ species ┃ island    ┃ bill_length_mm ┃ bill_depth_mm ┃ flipper_length_mm ┃ … ┃
┡━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━╇━━━┩
│ string  │ string    │ float64        │ float64       │ int64             │ … │
├─────────┼───────────┼────────────────┼───────────────┼───────────────────┼───┤
│ Adelie  │ Torgersen │           39.1 │          18.7 │               181 │ … │
│ Adelie  │ Torgersen │           39.5 │          17.4 │               186 │ … │
│ Adelie  │ Torgersen │           40.3 │          18.0 │               195 │ … │
│ Adelie  │ Torgersen │           NULL │          NULL │              NULL │ … │
│ Adelie  │ Torgersen │           36.7 │          19.3 │               193 │ … │
│ Adelie  │ Torgersen │           39.3 │          20.6 │               190 │ … │
│ Adelie  │ Torgersen │           38.9 │          17.8 │               181 │ … │
│ Adelie  │ Torgersen │           39.2 │          19.6 │               195 │ … │
│ Adelie  │ Torgersen │           34.1 │          18.1 │               193 │ … │
│ Adelie  │ Torgersen │           42.0 │          20.2 │               190 │ … │
│ …       │ …         │              … │             … │                 … │ … │
└─────────┴───────────┴────────────────┴───────────────┴───────────────────┴───┘

[ins] In [9]: t.bill_length_mm.mean()
Out[9]: 
┌──────────┐
│ 43.92193 │
└──────────┘

[ins] In [10]: t.filter(t.species.isin(["Dream", "Adelie"])).bill_length_mm.mean()
Out[10]: 
┌───────────┐
│ 38.791391 │
└───────────┘