(python) sorting date without using build in function

Question

python sorting date without using build in function sort() , but the expect i want is

['2010-01-12', '2010-01-14', '2010-02-07', '2010-02-11', '2010-11-16',
'2010-11-22', '2010-11-23', '2010-11-26', '2010-12-02', '2010-12-13',
'2011-02-04', '2011-06-02', '2011-08-05', '2011-11-30']

I did read the similar problem and try to sloved it but still stock
How to sort things, without using the sorted build-in function?
first version code:

import datetime

def date_sorting_operation(input_list):
  
  input_list = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in input_list] 

  for i in range(len(input_list)):
    for j in range(i + 1, len(input_list)):

        if l[i] > l[j]:
           l[i], l[j] = l[j], l[i]  
  return input_list

customer_date_list = ['2011-06-02', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']

print (date_sorting_operation(customer_date_list))

second version code:

import datetime

def date_sorting_operation(input_list):
  
  input_list = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in input_list] 

  for i in range(len(input_list) - 1):
     for j in range(0, len(input_list) - i - 1):
         if input_list[j].repeats > input_list[j + 1].repeats:
             input_list[j], input_list[j + 1] = input_list[j + 1], input_list[j] 
  return input_list

customer_date_list = ['2011-06-02', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']

print (date_sorting_operation(customer_date_list))

(pic) for code and output First version:

(pic) for code and output Second version:

(Third version) Try just to use "input_list", remove "new_list" to save memory if that, how can I do so?

   

import datetime
 
def date_sorting_operation(input_list):
  
  new_list = []
  dates = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in input_list] 
 
  while input_list:
      min = input_list[0]  
      for x in input_list: 
          if x < min:
              min = x
      new_list.append(min)
      input_list.remove(min)    
  return new_list
 
customer_date_list = ['2011-06-2', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']
 
print (date_sorting_operation(customer_date_list))

(pic) try just to use "input_list", remove "new_list" to save memory:

Asked By: j ton

||

Source

Answer 1

Actually your list of text dates are almost in an ISO sortable format, except that occasionally the month may be one digit instead of two. If we left pad the month with zero, sorting should work:

customer_date_list = ['2011-06-02', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']
output = [re.sub(r'-(d)-', r'-01-', x) for x in customer_date_list]
output.sort()
print(output)

['2010-01-12', '2010-01-14', '2010-02-07', '2010-02-11', '2010-12-02',
 '2010-12-13', '2011-02-04', '2011-06-02', '2011-08-05', '2011-11-30']

Answered By: Tim Biegeleisen

Answer 2

Try this

import datetime


customer_date_list = ['2011-06-02', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']

lst = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in customer_date_list]

outLst = []
for _ in customer_date_list:
    m = min(lst)
    lst.remove(m)
    outLst.append(m.strftime('%Y-%m-%d'))

print(outLst)

Output

['2010-01-12', '2010-01-14', '2010-02-07', '2010-02-11', '2010-12-02',
 '2010-12-13', '2011-02-04', '2011-06-02', '2011-08-05', '2011-11-30']

AS OP says "that can I just use one list lst, which without outLst, to save on the same list. (In saving memory purpose)"


import datetime


customer_date_list = ['2011-06-02', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30']

lst = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in customer_date_list]


for i in range(len(customer_date_list)):
    m = max(lst[i:])
    lst.remove(m)
    lst.insert(0,m.strftime('%Y-%m-%d'))

print(lst)

output

['2010-01-12', '2010-01-14', '2010-02-07', '2010-02-11', '2010-12-02',
 '2010-12-13', '2011-02-04', '2011-06-02', '2011-08-05', '2011-11-30']

Answered By: codester_09

(python) sorting date without using build in function

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