# -*- coding: utf-8 -*-
import numpy as np
from featuretools.primitives.base import TransformPrimitive
from featuretools.variable_types import Numeric, Text
[docs]class TitleWordCount(TransformPrimitive):
"""Determines the number of title words in a string.
Description:
Given list of strings, determine the number of title words
in each string. A title word is defined as any word starting
with a capital letter. Words at the start of a sentence will
be counted.
If a string is missing, return `NaN`.
Examples:
>>> x = ['My favorite movie is Jaws.', 'this is a string', 'AAA']
>>> title_word_count = TitleWordCount()
>>> title_word_count(x).tolist()
[2.0, 0.0, 1.0]
"""
name = "title_word_count"
input_types = [Text]
return_type = Numeric
default_value = 0
def get_function(self):
pattern = r'([A-Z][^\s]*)'
def title_word_count(x):
x = x.reset_index(drop=True)
counts = x.str.extractall(pattern).groupby(level=0).count()[0]
counts = counts.reindex_like(x).fillna(0)
counts[x.isnull()] = np.nan
return counts.astype(float)
return title_word_count