casting all columns of one type to another using selectors

[jjAtNxtPt]

I want to cast all columns of type "Decimal" to "Float64" without having to list them all out. I tried using the of_type() selector and chaining to cast() but I get the error that of_type() doesn't have a cast() attribute. The same error is given when I tried using the numeric() selector.

[lostmygithubaccount]

I think you're looking for something like this with s.across:

[ins] In [1]: import ibis

[ins] In [2]: ibis.options.interactive = True

[ins] In [3]: t = ibis.examples.penguins.fetch()

[ins] In [4]: t.head()
Out[4]:
┏━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━┳━━━━━━━┓
┃ species ┃ island    ┃ bill_length_mm ┃ bill_depth_mm ┃ flipper_length_mm ┃ body_mass_g ┃ sex    ┃ year  ┃
┡━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━╇━━━━━━━┩
│ string  │ string    │ float64        │ float64       │ int64             │ int64       │ string │ int64 │
├─────────┼───────────┼────────────────┼───────────────┼───────────────────┼─────────────┼────────┼───────┤
│ Adelie  │ Torgersen │           39.1 │          18.7 │               181 │        3750 │ male   │  2007 │
│ Adelie  │ Torgersen │           39.5 │          17.4 │               186 │        3800 │ female │  2007 │
│ Adelie  │ Torgersen │           40.3 │          18.0 │               195 │        3250 │ female │  2007 │
│ Adelie  │ Torgersen │           NULL │          NULL │              NULL │        NULL │ NULL   │  2007 │
│ Adelie  │ Torgersen │           36.7 │          19.3 │               193 │        3450 │ female │  2007 │
└─────────┴───────────┴────────────────┴───────────────┴───────────────────┴─────────────┴────────┴───────┘

[ins] In [5]: import ibis.selectors as s

[ins] In [6]: t.select(
         ...:     s.across(
         ...:         s.of_type(float),
         ...:         ibis._.cast("decimal")
         ...:     )
         ...: )
Out[6]:
┏━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ bill_length_mm ┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ decimal        │ decimal       │
├────────────────┼───────────────┤
│           39.1 │          18.7 │
│           39.5 │          17.4 │
│           40.3 │          18.0 │
│           NULL │          NULL │
│           36.7 │          19.3 │
│           39.3 │          20.6 │
│           38.9 │          17.8 │
│           39.2 │          19.6 │
│           34.1 │          18.1 │
│           42.0 │          20.2 │
│              … │             … │
└────────────────┴───────────────┘

[nav] In [7]: t.mutate(
         ...:     s.across(
         ...:         s.of_type(float),
         ...:         ibis._.cast("decimal")
         ...:     )
         ...: )
Out[7]:
┏━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━┳━━━━━━━┓
┃ species ┃ island    ┃ bill_length_mm ┃ bill_depth_mm ┃ flipper_length_mm ┃ body_mass_g ┃ sex    ┃ year  ┃
┡━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━╇━━━━━━━┩
│ string  │ string    │ decimal        │ decimal       │ int64             │ int64       │ string │ int64 │
├─────────┼───────────┼────────────────┼───────────────┼───────────────────┼─────────────┼────────┼───────┤
│ Adelie  │ Torgersen │           39.1 │          18.7 │               181 │        3750 │ male   │  2007 │
│ Adelie  │ Torgersen │           39.5 │          17.4 │               186 │        3800 │ female │  2007 │
│ Adelie  │ Torgersen │           40.3 │          18.0 │               195 │        3250 │ female │  2007 │
│ Adelie  │ Torgersen │           NULL │          NULL │              NULL │        NULL │ NULL   │  2007 │
│ Adelie  │ Torgersen │           36.7 │          19.3 │               193 │        3450 │ female │  2007 │
│ Adelie  │ Torgersen │           39.3 │          20.6 │               190 │        3650 │ male   │  2007 │
│ Adelie  │ Torgersen │           38.9 │          17.8 │               181 │        3625 │ female │  2007 │
│ Adelie  │ Torgersen │           39.2 │          19.6 │               195 │        4675 │ male   │  2007 │
│ Adelie  │ Torgersen │           34.1 │          18.1 │               193 │        3475 │ NULL   │  2007 │
│ Adelie  │ Torgersen │           42.0 │          20.2 │               190 │        4250 │ NULL   │  2007 │
│ …       │ …         │              … │             … │                 … │           … │ …      │     … │
└─────────┴───────────┴────────────────┴───────────────┴───────────────────┴─────────────┴────────┴───────┘

[jjAtNxtPt]

Thanks! That's it exacly!