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verticapy.vDataFrame.one_hot_encode

vDataFrame.one_hot_encode(columns: Annotated[str | list[str], 'STRING representing one column or a list of columns'] | None = None, max_cardinality: int = 12, prefix_sep: str = '_', drop_first: bool = True, use_numbers_as_suffix: bool = False) vDataFrame

Encodes the vDataColumns using the One Hot Encoding algorithm.

Parameters

columns: SQLColumns, optional

List of the vDataColumns used to train the One Hot Encoding model. If empty, only the vDataColumns with a cardinality less than ‘max_cardinality’ are used.

max_cardinality: int, optional

Cardinality threshold used to determine whether the vDataColumn is taken into account during the encoding This parameter is used only if the parameter ‘columns’ is empty.

prefix_sep: str, optional

Prefix delimitor of the dummies names.

drop_first: bool, optional

Drops the first dummy to avoid the creation of correlated features.

use_numbers_as_suffix: bool, optional

Uses numbers as suffix instead of the vDataColumns categories.

Returns

vDataFrame

self

Examples

We import verticapy:

import verticapy as vp

Hint

By assigning an alias to verticapy, we mitigate the risk of code collisions with other libraries. This precaution is necessary because verticapy uses commonly known function names like “average” and “median”, which can potentially lead to naming conflicts. The use of an alias ensures that the functions from verticapy are used as intended without interfering with functions from other libraries.

For this example, we will use the Titanic dataset.

import verticapy.datasets as vpd

data = vpd.load_titanic()
123
pclass
Integer
123
survived
Integer
Abc
Varchar(164)
Abc
sex
Varchar(20)
123
age
Numeric(8)
123
sibsp
Integer
123
parch
Integer
Abc
ticket
Varchar(36)
123
fare
Numeric(12)
Abc
cabin
Varchar(30)
Abc
embarked
Varchar(20)
Abc
boat
Varchar(100)
123
body
Integer
Abc
Varchar(100)
110male71.000PC 1760949.5042[null]C[null]22
210male45.00011378435.5TS[null][null]
310male[null]0011379831.0[null]S[null][null]
410male17.00011305947.1[null]S[null][null]
510male27.01013508136.7792C89C[null][null]
610male37.011PC 1775683.1583E52C[null][null]
710male31.010F.C. 1275052.0B71S[null][null]
810male50.010PC 17761106.425C86C[null]62
910female36.000PC 1753131.6792A29C[null][null]
1010male37.01011380353.1C123S[null][null]
1110male24.000PC 1759379.2B86C[null][null]
1210male45.0103697383.475C83S[null][null]
1310male40.0001120590.0B94S[null]110
1410male42.00011303842.5B11S[null][null]
1510male[null]001746351.8625E46S[null][null]
1610male42.01011378952.0[null]S[null]38
1710male[null]00PC 1760030.6958[null]C14[null]
1810male29.00011350130.0D6S[null]126
1910male46.0001305075.2417C6C[null]292
2010male54.0001746351.8625E46S[null]175
2110male47.00011379642.4[null]S[null][null]
2210male58.00235273113.275D48C[null]122
2310male45.50011304328.5C124S[null]166
2410male29.01011377666.6C2S[null][null]
2510male47.00011046552.0C110S[null]207
2610male38.000199720.0[null]S[null][null]
2710male22.000PC 17760135.6333[null]C[null]232
2810male31.000PC 1759050.4958A24S[null][null]
2910male50.0101350755.9E44S[null][null]
3010male56.0001776430.6958A7C[null][null]
3110male57.010PC 17569146.5208B78C[null][null]
3210female63.010PC 17483221.7792C55 C57S[null][null]
3310male61.0003696332.3208D50S[null]46
3410male21.0013528177.2875D26S[null]169
3510male51.001PC 1759761.3792[null]C[null][null]
3611female63.0101350277.9583D7S10[null]
3711female32.0001181376.2917D15C8[null]
3811female58.00011378326.55C103S8[null]
3911female44.000PC 1761027.7208B4C6[null]
4011female41.00016966134.5E40C3[null]
4111female53.000PC 1760627.4458[null]C6[null]
4211male36.001PC 17755512.3292B51 B53 B55C3[null]
4311female58.001PC 17755512.3292B51 B53 B55C3[null]
4411male11.012113760120.0B96 B98S4[null]
4511female76.0101987778.85C46S6[null]
4611female[null]0111350555.0E33S6[null]
4711female39.011PC 1775683.1583E49C14[null]
4811female27.012F.C. 1275052.0B71S3[null]
4911female[null]0017421110.8833[null]C4[null]
5011female35.000113503211.5C130C4[null]
5111female22.00111237859.4[null]C7[null]
5211female25.0101176555.4417E50C5[null]
5311male48.010PC 1757276.7292D33C3[null]
5411female35.0103697383.475C83SD[null]
5511male27.000PC 1757276.7292D49C3[null]
5611female24.0001176783.1583C54C7[null]
5711female52.0111274993.5B69S3[null]
5811female44.00111136157.9792B18C4[null]
5911female15.00124160211.3375B5S2[null]
6011male30.0101323657.75C78C11[null]
6111female31.01035273113.275D36C6[null]
6211female39.000PC 17758108.9C105C8[null]
6311female22.00111350961.9792B36C5[null]
6411male52.00011378630.5C104S6[null]
6511female43.00124160211.3375B3S2[null]
6611female33.00011015286.5B77S8[null]
6711male45.01116966134.5E34C3[null]
6811female40.01116966134.5E34C3[null]
6911male48.0101999652.0C126S5 7[null]
7011female[null]00PC 1758579.2[null]CD[null]
7111female35.000PC 17755512.3292[null]C3[null]
7211female60.01011081375.25D37C5[null]
7311male21.001PC 1759761.3792[null]CA[null]
7420male23.000C.A. 3103010.5[null]S[null][null]
7520male28.00024435826.0[null]S[null][null]
7620male60.0112975039.0[null]S[null][null]
7720female44.01024425226.0[null]S[null][null]
7820male29.010200326.0[null]S[null][null]
7920male18.000S.O.C. 1487973.5[null]S[null][null]
8020male18.000S.O.C. 1487973.5[null]S[null][null]
8120male54.0002840326.0[null]S[null][null]
8220male18.00023617113.0[null]S[null][null]
8320male36.00022923613.0[null]S[null]236
8420male34.0102866421.0[null]S[null][null]
8520male21.0102813311.5[null]S[null][null]
8620male21.0102813411.5[null]S[null][null]
8720male24.00023386613.0[null]S[null]155
8820male34.0001223313.0[null]S[null][null]
8920male30.00025065313.0[null]S[null]75
9020male44.00024874613.0[null]S[null]35
9120male49.01222084565.0[null]S[null][null]
9220male21.020S.O.C. 1487973.5[null]S[null][null]
9320male21.000S.O.C. 1487973.5[null]S[null][null]
9420female60.0102406526.0[null]S[null][null]
9520male24.020C.A. 3102931.5[null]S[null][null]
9620male22.020C.A. 3102931.5[null]S[null][null]
9720male35.00023373412.35[null]Q[null][null]
9820male31.000C.A. 1872310.5[null]S[null]165
9920male36.000SC/Paris 216312.875DC[null][null]
10020male[null]00SC/A.3 286115.5792[null]C[null][null]
Rows: 1-100 | Columns: 14

Note

VerticaPy offers a wide range of sample datasets that are ideal for training and testing purposes. You can explore the full list of available datasets in the Datasets, which provides detailed information on each dataset and how to use them effectively. These datasets are invaluable resources for honing your data analysis and machine learning skills within the VerticaPy environment.

Let’s select few categorical features

data = data.select(["pclass", "sex", "survived", "embarked"])
data
123
pclass
Integer
100%
...
Abc
sex
Varchar(20)
100%
Abc
embarked
Varchar(20)
99%
11...maleC
21...maleS
31...maleS
41...maleS
51...maleC
61...maleC
71...maleS
81...maleC
91...femaleC
101...maleS
111...maleC
121...maleS
131...maleS
141...maleS
151...maleS
161...maleS
171...maleC
181...maleS
191...maleC
201...maleS

Let’s apply encoding on all the vcolumns of the datasets

data.one_hot_encode()
123
pclass
Integer
100%
...
123
embarked_C
Bool
100%
123
embarked_Q
Bool
100%
11...10
21...00
31...00
41...00
51...10
61...10
71...00
81...10
91...10
101...00
111...10
121...00
131...00
141...00
151...00
161...00
171...10
181...00
191...10
201...00

Let’s apply encoding on two specific vcolumns viz. “pclass” and “embarked”

data = data.select(["pclass", "sex", "survived", "embarked"])
data.one_hot_encode(columns = ["pclass", "embarked"])
123
pclass
Integer
100%
...
Abc
sex
Varchar(20)
100%
123
embarked_Q
Bool
100%
11...male0
21...male0
31...male0
41...male0
51...male0
61...male0
71...male0
81...male0
91...female0
101...male0
111...male0
121...male0
131...male0
141...male0
151...male0
161...male0
171...male0
181...male0
191...male0
201...male0

Let’s apply encoding on all features having cardinality less than 3

data = data.select(["pclass", "sex", "survived", "embarked"])
data.one_hot_encode(
    max_cardinality = 3,
    drop_first = False,
)
123
pclass
Integer
100%
...
Abc
sex
Varchar(20)
100%
123
sex_male
Bool
100%
11...male1
21...male1
31...male1
41...male1
51...male1
61...male1
71...male1
81...male1
91...female0
101...male1
111...male1
121...male1
131...male1
141...male1
151...male1
161...male1
171...male1
181...male1
191...male1
201...male1

See also

vDataFrame.decode() : User Defined Encoding.
vDataFrame.label_encode() : Label Encoding.
vDataFrame.mean_encode() : Mean Encoding.
vDataFrame.discretize() : Discretization.