Date Extractor

The project involves extraction of dates from sentences consisting of a date or a keyword relating to some date. The output date is displayed in DD-MM-YYYY format. It displays date for all the tokens that can be tagged to some date.

Instructions for Usage

For using the script, you must have Python's nltk library installed. Use the following command for installing nltk.

$ sudo pip3 install nltk

Clone the repository by using the following command:

$ git clone https://github.com/ankit0905/date-extractor.git

Git must be installed for the above command to work. After you have cloned the repo, cd to the cloned directory.

$ python3 main.py 

When you run, you will get a prompt asking for input. A sample output is displayed below.

$ python3 main.py
Enter Input: We went to the mall on 2nd and will go again tomorrow.

tomorrow  =>  07-07-2017
2nd  =>  02-07-2017

Project Documentation

The project has been done in Python3 and using its modules - datetime, nltk (natural language processing toolkit) and re (regular expressions).

Class Reference

The project consists on only one class as for now - namely the CustomDate class.

CustomDate Class

Methods

• __ init __(self, user_input)
• convert(self)
• getDate(self)
• next_weekday(self, d, weekday)
• previous_weekday(self, d, weekday)

Class Description:
The CustomDate class is responsible for converting a date in some format or some keyword relating to a date to DD-MM-YYYY format date. The class uses Python's datetime library in the process.

Method Documentation

1. __ init __ (self, user_input)
   This is the constructor method for the CustomDate class. The only parameter it takes in the user_input which is actually the processed form of user_input after using tokenization and n-grams. In the constuctor, several initializations of the member variables - output_date, date, month, year, errors take place.

2. convert(self)
   The method is used only when the user_input passed to the class constructor method consists of numeric values. If there is some valid date, the method will process it accordingly and convert it into DD-MM-YYYY format date.

3. getDate(self)
   This is the complementary method of self.convert() - used only when there are no numeric value in the input sequence. It checks if the input is a valid combination of keywords that relates to a date. If a valid date is obtained, it stores the date in DD-MM-YY format in the member variable called self.output_date. Otherwise, the self.errors member varibale in set indicating invalid input.

4. next_weekday(self, d, weekday)
   Given some date (d here) and the weekday required, it returns the date in DD-MM-YYYY format for the coming weekday.

5. previous_weekday(self, d, weekday)
   Given some date (d here) and the weekday required, it returns the date in DD-MM-YYYY format for the last weekday.

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NOTE:

1. The project has scope for further improvements, some of which are:

   • Distinguishing Names from Months
     ex: "April" can be a name of some person and also is a month name.
   • Identifying Tense in the sentence for more appropriate outputs.
     ex: Consider the sentence: "I went to the mall on Monday". A valid output here should be the date of last monday, but currently it outputs the date of coming Monday.

2. Any suggestions for improvements are welcome.