Double for loop with dates in array

[leifeng]

I have a SQLite database that I've selected into an array cursor where each row has a date element. I've already sorted cursor by date.

I effectively have something like:

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cursor = [     [data1, "date", date2, date3],     [data1, "date", date2, date3],     [data1, "date", date2, date3],     [data1, "date", date2, date3] ]

Using two for loops, I want to write a string for each row, group them together by day, and then group and write those days by month per year.

In the end, it should have:

-> 2020-02.txt

2020-02-01

data
data

2020-02-02

data

2020-02-05

data

-> 2020-03.txt

2020-03-02

data

2020-03-05

data

And so on.

I'm having trouble how to actually structure the for loops to end the "day" and begin another "day", and the same for a "month".

For now, all I have is:

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date_test = date.fromisoformat(cursor[0][2]) for idx, val in enumerate(sorted(cursor, key=lambda row: row[2])):     # Check if the year is different     if date_test.strftime("%Y") != date.fromisoformat(val[2]).strftime("%Y"):         # Check if month is different...         pass

[leifeng]

I've written some code that does the work but it is horribly structured:

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cursor.execute("""SELECT * FROM log""")     records = cursor.fetchall()     date_index = date.fromisoformat(records[0][2])     log_file = open("{}.txt".format(date_index.strftime("%Y-%m")), "w")     log_file.write("""b{}/b:   list """.format(date_index.strftime("%Y-%m-%d")))     for idx, val in enumerate(sorted(records, key=lambda row: row[2])):         date_val = date.fromisoformat(val[2])         print(date_index, date_val)                   # Check if the date is different         if date_index != date_val:             print("DEBUG: Date changed")                           # Check if day is different so we closed the list.             if date_index.day != date_val.day:                 log_file.write("""/list   """)                 print("DEBUG: Day changed")                               # The month or year is different so we close the file and open an new one             if date_index.year != date_val.year or date_index.month != date_val.month:                 log_file.close()                 log_file = open("{}.txt".format(date_val.strftime("%Y-%m")), "w")                 log_file.write("""b{}/b:               list """.format(date_val.strftime("%Y-%m-%d")))                 print("DEBUG: month or year changed")             if date_index.year == date_val.year and date_index.month == date_val.month:             # The month and year is the same so we open a new list for this day                 log_file.write("""b{}/b:               list """.format(date_val.strftime("%Y-%m-%d")))             date_index = date_val         print(val, idx)         log_file.write(''.join('{}'.format(val)))