def feature_bag_of_words(
x_train, x_test=None, list_of_cols=[], keep_col=False, **algo_kwargs
):
"""
Creates a matrix of how many times a word appears in a document.
Parameters
----------
x_train : DataFrame
Training dataset, by default None
x_test : DataFrame
Testing dataset, by default None
list_of_cols : list, optional
A list of specific columns to apply this technique to., by default []
keep_col : bool, optional
True if you want to keep the columns passed, otherwise remove it.
algo_kwargs : dict, optional
Parameters you would pass into Bag of Words constructor as a dictionary., by default {}
Returns
-------
Dataframe, *Dataframe
Transformed dataframe with the new column.
Returns 2 Dataframes if x_test is provided.
"""
enc = CountVectorizer(**algo_kwargs)
list_of_cols = _get_columns(list_of_cols, x_train)
for col in list_of_cols:
enc_data = enc.fit_transform(x_train[col]).toarray()
enc_df = pd.DataFrame(enc_data, columns=enc.get_feature_names())
x_train = drop_replace_columns(x_train, col, enc_df, keep_col)
if x_test is not None:
enc_x_test = enc.transform(x_test[col]).toarray()
enc_test_df = pd.DataFrame(enc_x_test, columns=enc.get_features_names())
x_test = drop_replace_columns(x_test, col, enc_test_df, keep_col)
return x_train, x_test
import pandas as pd
df = pd.read_csv('movie_data.csv', encoding='utf-8')
from sklearn.feature_extraction.text import CountVectorizer
count = CountVectorizer(stop_words='english', max_df=.1, max_features=5000)
X = count.fit_transform(df['review'].values)
from sklearn.decomposition import LatentDirichletAllocation
lda = LatentDirichletAllocation(n_topics=10, random_state=123, learning_method='batch')
X_topics = lda.fit_transform(X)
lda.components_.shape
n_top_words = 5
feature_name = count.get_features_names()
for topic_idx, topic in enumerate(lda.components_):
print('Topic %d:' % (topic_idx + 1))
print(' '.join([feature_names[i] for i in topic.argsort() \ [:-n_top_words - 1:-1]]))
