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"""Character level TFIDF and Count followed by Truncated SVD on text columns"""
from h2oaicore.transformer_utils import CustomTransformer
import datatable as dt
import numpy as np
import string
from sklearn.feature_extraction.text import CountVectorizer, TfidfVectorizer
from sklearn.decomposition import TruncatedSVD
class TextCharTFIDFTransformer(CustomTransformer):
_testing_can_skip_failure = False # ensure tested as if shouldn't fail
def __init__(self, max_ngram, n_svd_comp, **kwargs):
super().__init__(**kwargs)
self.max_ngram = max_ngram
self.n_svd_comp = n_svd_comp
@staticmethod
def do_acceptance_test():
return True
@staticmethod
def get_default_properties():
return dict(col_type="text", min_cols=1, max_cols=1, relative_importance=1)
@staticmethod
def get_parameter_choices():
return {"max_ngram": [3, 2, 1],
"n_svd_comp": [50, 20, 100]}
@property
def display_name(self):
return f"CharTFIDF_{self.max_ngram}maxgram_SVD_{self.n_svd_comp}comp"
def fit_transform(self, X: dt.Frame, y: np.array = None):
X = X.to_pandas().astype(str).iloc[:, 0].fillna("NA")
# TFIDF Vectorizer
self.tfidf_vec = TfidfVectorizer(analyzer="char", ngram_range=(1, self.max_ngram))
X = self.tfidf_vec.fit_transform(X)
# Truncated SVD
if len(self.tfidf_vec.vocabulary_) <= self.n_svd_comp:
self.n_svd_comp = len(self.tfidf_vec.vocabulary_) - 1
self.truncated_svd = TruncatedSVD(n_components=self.n_svd_comp, random_state=2019)
X = self.truncated_svd.fit_transform(X)
return X
def transform(self, X: dt.Frame):
X = X.to_pandas().astype(str).iloc[:, 0].fillna("NA")
X = self.tfidf_vec.transform(X)
X = self.truncated_svd.transform(X)
return X
class TextCharCountTransformer(CustomTransformer):
_testing_can_skip_failure = False # ensure tested as if shouldn't fail
def __init__(self, max_ngram, n_svd_comp, **kwargs):
super().__init__(**kwargs)
self.max_ngram = max_ngram
self.n_svd_comp = n_svd_comp
@staticmethod
def do_acceptance_test():
return True
@staticmethod
def get_default_properties():
return dict(col_type="text", min_cols=1, max_cols=1, relative_importance=1)
@staticmethod
def get_parameter_choices():
return {"max_ngram": [3, 2, 1],
"n_svd_comp": [50, 20, 100]}
@property
def display_name(self):
return f"CharCount_max{self.max_ngram}gram_SVD_{self.n_svd_comp}comp"
def fit_transform(self, X: dt.Frame, y: np.array = None):
X = X.to_pandas().astype(str).iloc[:, 0].fillna("NA")
# Count Vectorizer
self.cnt_vec = CountVectorizer(analyzer="char", ngram_range=(1, self.max_ngram))
X = self.cnt_vec.fit_transform(X)
# Truncated SVD
if len(self.cnt_vec.vocabulary_) <= self.n_svd_comp:
self.n_svd_comp = len(self.cnt_vec.vocabulary_) - 1
self.truncated_svd = TruncatedSVD(n_components=self.n_svd_comp, random_state=2019)
X = self.truncated_svd.fit_transform(X)
return X
def transform(self, X: dt.Frame):
X = X.to_pandas().astype(str).iloc[:, 0].fillna("NA")
X = self.cnt_vec.transform(X)
X = self.truncated_svd.transform(X)
return X