date_to_weekday: new implementation replaces buggy original

Author: spazm

other/date_to_weekday.py

@@ -3,28 +3,144 @@
 from calendar import day_name
 from datetime import datetime
 
+"""
+Family of functions for calculating the day of week name from a date
+"""
 
-def date_to_weekday(inp_date: str) -> str:
+
+def day_of_week(datetime_obj: datetime) -> str:
     """
-    It returns the day name of the given date string.
-    :param inp_date:
+    Calculates the day name of the given datetime object
+    :param datetime_obj:
     :return: String
-    >>> date_to_weekday("7/8/2035")
+    >>> day_of_week(datetime(year=2035, month=8, day=7))
     'Tuesday'
-    >>> date_to_weekday("7/8/2021")
+    >>> day_of_week(datetime(year=2021, month=8, day=7))
     'Saturday'
-    >>> date_to_weekday("1/1/2021")
+    >>> day_of_week(datetime(year=2021, month=8, day=1))
+    'Sunday'
+    >>> day_of_week(datetime(year=2021, month=1, day=1))
     'Friday'
+    >>> day_of_week(datetime(year=2021, month=1, day=31))
+    'Sunday'
+    """
+    day_of_week: int = datetime_obj.weekday()  # Monday = 0 .. Sunday = 6
+    return day_name[day_of_week]
+
+
+def day_of_week_fmt(date_string: str, format: str = "%Y%m%d") -> str:
     """
-    year: int | str
-    day, month, year = (int(x) for x in inp_date.split("/"))
-    if year % 100 == 0:
-        year = "00"
-    new_base_date: str = f"{day}/{month}/{year%100} 0:0:0"
-    date_time_obj: datetime = datetime.strptime(new_base_date, "%d/%m/%y %H:%M:%S")
-    out_put_day: int = date_time_obj.weekday()
-    return day_name[out_put_day]
+    Calculates the day name of the given date string decoded by format.
+
+    See time.strptime for format parameters.
+
+    :param date_string: date in dd/mm/yyyy format
+    :param format: strptime compatible date format
+    :return: String
+
+    >>> day_of_week_fmt("20211026")
+    'Tuesday'
+    >>> day_of_week_fmt("2021/10/26", "%Y/%m/%d")
+    'Tuesday'
+    >>> day_of_week_fmt("2021-10-26", "%Y-%m-%d")
+    'Tuesday'
+    >>> day_of_week_fmt("7/8/2021", "%d/%m/%Y")
+    'Saturday'
+    >>> day_of_week_fmt("7/8/2021", "%m/%d/%Y")
+    'Thursday'
+    """
+    datetime_obj = datetime.strptime(date_string, format)
+    return day_of_week(datetime_obj)
+
+
+def day_of_week_dmy(date_string: str) -> str:
+    """
+    Calculates the day name of the given date string in day/month/year format
+
+    :param datestring: date in dd/mm/yyyy format
+    :return: String
+    >>> day_of_week_dmy("7/8/2035")
+    'Tuesday'
+    >>> day_of_week_dmy("7/8/2021")
+    'Saturday'
+    >>> day_of_week_dmy("7/08/2021")
+    'Saturday'
+    >>> day_of_week_dmy("07/8/2021")
+    'Saturday'
+    >>> day_of_week_dmy("07/08/2021")
+    'Saturday'
+    >>> day_of_week_dmy("1/1/2021")
+    'Friday'
+    >>> day_of_week_dmy("31/1/2021")
+    'Sunday'
+    """
+    return day_of_week_fmt(date_string, format="%d/%m/%Y")
+
+
+def day_of_week_mdy(date_string: str) -> str:
+    """
+    Calculates the day name of the given date string.
+    :param date_mdy: date in mm/dd/yyyy format
+    :return: String
+    >>> day_of_week_mdy("8/7/2035")
+    'Tuesday'
+    >>> day_of_week_mdy("8/7/2021")
+    'Saturday'
+    >>> day_of_week_mdy("8/07/2021")
+    'Saturday'
+    >>> day_of_week_mdy("1/31/2021")
+    'Sunday'
+    >>> day_of_week_mdy("01/31/2021")
+    'Sunday'
+    """
+    return day_of_week_fmt(date_string, format="%m/%d/%Y")
+
+
+def day_of_week_ymd(date_string: str) -> str:
+    """
+    >>> day_of_week_ymd("2035/07/08")
+    'Sunday'
+    >>> day_of_week_ymd("2021/7/8")
+    'Thursday'
+    >>> day_of_week_ymd("2021/1/1")
+    'Friday'
+    """
+    return day_of_week_fmt(date_string, format="%Y/%m/%d")
 
 
 if __name__ == "__main__":
-    print(date_to_weekday("1/1/2021"), end=" ")
+    print("Tuesday August 7, 2035:\n    ",
+          day_of_week_fmt("7/8/2035", format="%d/%m/%Y"),
+          day_of_week_fmt("8/07/2035", format="%m/%d/%Y"),
+          day_of_week_fmt("2035-08-07", format="%Y-%m-%d"),
+          day_of_week_fmt("20350807"),
+          day_of_week_dmy("7/8/2035"),
+          day_of_week_mdy("8/7/2035"),
+          day_of_week_ymd("2035/08/07"))
+
+    print("Sunday August 7, 2021:\n    ",
+          day_of_week_fmt("7/8/2021", format="%d/%m/%Y"),
+          day_of_week_fmt("8/07/2021", format="%m/%d/%Y"),
+          day_of_week_fmt("2021-08-07", format="%Y-%m-%d"),
+          day_of_week_fmt("20210807"),
+          day_of_week_dmy("7/8/2021"),
+          day_of_week_mdy("8/7/2021"),
+          day_of_week_ymd("2021/08/07"))
+
+    print("Friday January 1, 2021:\n    ",
+          day_of_week_fmt("1/1/2021", format="%d/%m/%Y"),
+          day_of_week_fmt("1/1/2021", format="%m/%d/%Y"),
+          day_of_week_fmt("2021-01-01", format="%Y-%m-%d"),
+          day_of_week_fmt("20210101"),
+          day_of_week_dmy("1/1/2021"),
+          day_of_week_mdy("1/1/2021"),
+          day_of_week_ymd("2021/01/1"))
+
+    print("Friday October 1, 2021:\n    ",
+          day_of_week_fmt("1/10/2021", format="%d/%m/%Y"),
+          day_of_week_fmt("10/1/2021", format="%m/%d/%Y"),
+          day_of_week_fmt("2021-10-01", format="%Y-%m-%d"),
+          day_of_week_fmt("20211001"),
+          day_of_week_dmy("1/10/2021"),
+          day_of_week_mdy("10/1/2021"),
+          day_of_week_ymd("2021/10/01"))