CODEWITHSUNDEEP
python
Bucket8
Bucket8

Reputation: 11

Removing the year from date in a list in python

I'm trying to take the /15 off the dates in this array. The array is ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15'] and is named dateList.

def changeDateLength(dateList):
    dateLength = dateList[0]  
    newList = []

    for date in dateList:
       if len(dateLength[0]) > 7:
          shortDateLength = dateLength[:5]
       else:
          shortDateLength = dateLength[:4]
       newList.append(shore)
    return newList

the list prints out as ['6/03', '6/03', '6/03', '6/03', '6/03', '6/03', '6/03', '6/03', '6/03', '6/03']

Upvotes: 1

Views: 608

Answers (5)

Andrzej Pronobis
Andrzej Pronobis

Reputation: 36106

The simplest solution (given quite strict assumptions about the format of the date) would be:

[d[:-3] for d in dateList]

resulting in:

['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']

Upvotes: 0

Alex Boklin
Alex Boklin

Reputation: 91

Regular expressions are also a nice solution to the problem:

import re

dateList = ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
result = [ i[:-3] for i in re.findall(r"\d{,2}/\d{,2}/15", str(dateList)) ]
print(result) # ['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']

In case if you have dates with some other years that you do not want to touch:

dateList = ['8/12/14', '25/01/03', '6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
result = [ i[:-3] if i in re.findall(r"\d{,2}/\d{,2}/15", str(dateList)) else i for i in dateList ]
print(result) # ['8/12/14', '25/01/03', '6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']

Upvotes: 0

Vivek Sable
Vivek Sable

Reputation: 10223

By List Comprehension :

Iterate every element from the given list and split element by / and again join first two item from the split result by /

>>> l
['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
>>> ["/".join(i.split("/")[:2]) for i in l ]
['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']

About Your Code:

Your Code:

def changeDateLength(dateList):
    #- Why first item from the list is consider? This will raise exception IndexError
    # when input is empty list.
    # So not need to this.
    dateLength = dateList[0]

    #- Yes correct need new list varable. 
    newList = []

    for date in dateList:
        #- We iterate item from the list.
        # so do process on item . dateLength[0] means first character from the dateLength variable which length is always 1.
        # 1 > 7 will return False.
        if len(dateLength[0]) > 7:
            shortDateLength = dateLength[:5]
        else:
            shortDateLength = dateLength[:4]

        #= Raise NameError exception because shore is not define
        newList.append(shore)   

    return newList

Try:

def changeDateLength(dateList):
    newList = []
    for date_item in dateList:
        if len(date_item) > 7:
            shortDateLength = date_item[:5]
        else:
            shortDateLength = date_item[:4]
        newList.append(shortDateLength)

    return newList


dateList =  ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
new_dateList = changeDateLength(dateList)
print "new_dateList:", new_dateList

Upvotes: 3

rmmh
rmmh

Reputation: 7095

Since you're using dates, you can use the time module to parse and format it.

import time

def strip_year(date):
    return time.strftime('%-m/%d', time.strptime(date, '%d/%m/%y'))

Upvotes: 0

user1823
user1823

Reputation: 1111

Try the following simple list comprehension, we split by '/', take all up to the last item, and join the with a '/':

def changeDateLength(datelist):
    return ['/'.join(item.split('/')[:-1]) for item in datelist]

>>> dateList = ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
>>> changeDateLength(dateList)
['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']
>>>

Upvotes: 0

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