How to extract or validate date format from a text using python? - python-3.x

Question

I'm trying to execute this code:
import datefinder
string_with_dates = 'The stock has a 04/30/2009 great record of positive Sept 1st, 2005 earnings surprises, having beaten the trade Consensus EPS estimate in each of the last four quarters. In its last earnings report on May 8, 2018, Triple-S Management reported EPS of $0.6 vs.the trade Consensus of $0.24 while it beat the consensus revenue estimate by 4.93%.'
matches = datefinder.find_dates(string_with_dates)
for match in matches:
print(match)
The output is:
2009-04-30 00:00:00
2005-09-01 00:00:00
2018-05-08 00:00:00
2019-02-04 00:00:00
The last date has come due to the percentage value 4.93% ... How to overcome this situation?

Answer 1

I cannot fix the datefinder module issue. You stated that you needed a solution, so I put this together for you. It's a work in progress, which means that you can adjusted it as needed. Also, some of the regex could have been consolidated, but I wanted to break them out for you. Hopefully, this answer helps you until you find another solution that works better for your needs.
import re
string_with_dates = 'The stock has a 04/30/2009 great record of positive Sept 1st, 2005 earnings surprises having beaten the trade Consensus EPS estimate in each of the last ' \
'four quarters In its last earnings report on March 8, 2018, Triple-S Management reported EPS of $0.6 vs.the trade Consensus of $0.24 while it beat the ' \
'consensus revenue estimate by 4.93%. The next trading day will occur at 2019-02-15T12:00:00-06:30'
def find_dates(input):
'''
This function is used to extract date strings from provide text.
Symbol references:
YYYY = four-digit year
MM = two-digit month (01=January, etc.)
DD = two-digit day of month (01 through 31)
hh = two digits of hour (00 through 23) (am/pm NOT allowed)
mm = two digits of minute (00 through 59)
ss = two digits of second (00 through 59)
s = one or more digits representing a decimal fraction of a second
TZD = time zone designator (Z or +hh:mm or -hh:mm)
:param input: text
:return: date string
'''
date_formats = [
# Matches date format MM/DD/YYYY
'(\d{2}\/\d{2}\/\d{4})',
# Matches date format MM-DD-YYYY
'(\d{2}-\d{2}-\d{4})',
# Matches date format YYYY/MM/DD
'(\d{4}\/\d{1,2}\/\d{1,2})',
# Matches ISO 8601 format (YYYY-MM-DD)
'(\d{4}-\d{1,2}-\d{1,2})',
# Matches ISO 8601 format YYYYMMDD
'(\d{4}\d{2}\d{2})',
# Matches full_month_name dd, YYYY or full_month_name dd[suffixes], YYYY
'(January|February|March|April|May|June|July|August|September|October|November|December)(\s\d{1,2}\W\s\d{4}|\s\d(st|nd|rd|th)\W\s\d{4})',
# Matches abbreviated_month_name dd, YYYY or abbreviated_month_name dd[suffixes], YYYY
'(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sept|Oct|Nov|Dec)(\s\d{1,2}\W\s\d{4}|\s\d(st|nd|rd|th)\W\s\d{4})',
# Matches ISO 8601 format with time and time zone
# yyyy-mm-ddThh:mm:ss.nnnnnn+|-hh:mm
'\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\+|-)\d{2}:\d{2}',
# Matches ISO 8601 format Datetime with timezone
# yyyymmddThhmmssZ
'\d{8}T\d{6}Z',
# Matches ISO 8601 format Datetime with timezone
# yyyymmddThhmmss+|-hhmm
'\d{8}T\d{6}(\+|-)\d{4}'
]
for item in date_formats:
date_format = re.compile(r'\b{}\b'.format(item), re.IGNORECASE|re.MULTILINE)
find_date = re.search(date_format, input)
if find_date:
print (find_date.group(0))
find_dates(string_with_dates)
# outputs
04/30/2009
March 8, 2018
Sept 1st, 2005
2019-02-15T12:00:00-06:30