add Python implementation

Author: picnixz

Lib/_pydatetime.py

@@ -165,14 +165,23 @@ def _build_struct_time(y, m, d, hh, mm, ss, dstflag):
     dnum = _days_before_month(y, m) + d
     return _time.struct_time((y, m, d, hh, mm, ss, wday, dnum, dstflag))
 
-def _format_time(hh, mm, ss, us, timespec='auto'):
-    specs = {
-        'hours': '{:02d}',
-        'minutes': '{:02d}:{:02d}',
-        'seconds': '{:02d}:{:02d}:{:02d}',
-        'milliseconds': '{:02d}:{:02d}:{:02d}.{:03d}',
-        'microseconds': '{:02d}:{:02d}:{:02d}.{:06d}'
-    }
+def _format_time(hh, mm, ss, us, timespec='auto', basic=False):
+    if basic:
+        specs = {
+            'hours': '{:02d}',
+            'minutes': '{:02d}{:02d}',
+            'seconds': '{:02d}{:02d}{:02d}',
+            'milliseconds': '{:02d}{:02d}{:02d}.{:03d}',
+            'microseconds': '{:02d}{:02d}{:02d}.{:06d}'
+        }
+    else:
+        specs = {
+            'hours': '{:02d}',
+            'minutes': '{:02d}:{:02d}',
+            'seconds': '{:02d}:{:02d}:{:02d}',
+            'milliseconds': '{:02d}:{:02d}:{:02d}.{:03d}',
+            'microseconds': '{:02d}:{:02d}:{:02d}.{:06d}'
+        }
 
     if timespec == 'auto':
         # Skip trailing microseconds when us==0.
@@ -1051,16 +1060,18 @@ def __format__(self, fmt):
             return self.strftime(fmt)
         return str(self)
 
-    def isoformat(self):
+    def isoformat(self, basic=False):
         """Return the date formatted according to ISO.
 
-        This is 'YYYY-MM-DD'.
+        This is 'YYYY-MM-DD' or 'YYYYMMDD' if *basic* is true.
 
         References:
         - http://www.w3.org/TR/NOTE-datetime
         - http://www.cl.cam.ac.uk/~mgk25/iso-time.html
         """
-        return "%04d-%02d-%02d" % (self._year, self._month, self._day)
+        if basic:
+            return f"{self._year:04d}{self._month:02d}{self._day:02d}"
+        return f"{self._year:04d}-{self._month:02d}-{self._day:02d}"
 
     __str__ = isoformat
 
@@ -1501,10 +1512,11 @@ def __hash__(self):
 
     # Conversion to string
 
-    def _tzstr(self):
+    def _tzstr(self, basic):
         """Return formatted timezone offset (+xx:xx) or an empty string."""
         off = self.utcoffset()
-        return _format_offset(off)
+        sep = '' if basic else ':'
+        return _format_offset(off, sep)
 
     def __repr__(self):
         """Convert to formal string, for repr()."""
@@ -1525,19 +1537,21 @@ def __repr__(self):
             s = s[:-1] + ", fold=1)"
         return s
 
-    def isoformat(self, timespec='auto'):
+    def isoformat(self, timespec='auto', basic=False):
         """Return the time formatted according to ISO.
 
         The full format is 'HH:MM:SS.mmmmmm+zz:zz'. By default, the fractional
         part is omitted if self.microsecond == 0.
 
+        If *basic* is true, separators ':' are removed from the output.
+
         The optional argument timespec specifies the number of additional
         terms of the time to include. Valid options are 'auto', 'hours',
         'minutes', 'seconds', 'milliseconds' and 'microseconds'.
         """
         s = _format_time(self._hour, self._minute, self._second,
-                          self._microsecond, timespec)
-        tz = self._tzstr()
+                         self._microsecond, timespec, basic)
+        tz = self._tzstr(basic)
         if tz:
             s += tz
         return s
@@ -2028,6 +2042,12 @@ def astimezone(self, tz=None):
 
     # Ways to produce a string.
 
+    def _tzstr(self, basic):
+        """Return formatted timezone offset (+xx:xx) or an empty string."""
+        off = self.utcoffset()
+        sep = '' if basic else ':'
+        return _format_offset(off, sep)
+
     def ctime(self):
         "Return ctime() style string."
         weekday = self.toordinal() % 7 or 7
@@ -2038,12 +2058,14 @@ def ctime(self):
             self._hour, self._minute, self._second,
             self._year)
 
-    def isoformat(self, sep='T', timespec='auto'):
+    def isoformat(self, sep='T', timespec='auto', basic=False):
         """Return the time formatted according to ISO.
 
         The full format looks like 'YYYY-MM-DD HH:MM:SS.mmmmmm'.
         By default, the fractional part is omitted if self.microsecond == 0.
 
+        If *basic* is true, separators ':' and '-' are removed from the output.
+
         If self.tzinfo is not None, the UTC offset is also attached, giving
         giving a full format of 'YYYY-MM-DD HH:MM:SS.mmmmmm+HH:MM'.
 
@@ -2054,12 +2076,12 @@ def isoformat(self, sep='T', timespec='auto'):
         terms of the time to include. Valid options are 'auto', 'hours',
         'minutes', 'seconds', 'milliseconds' and 'microseconds'.
         """
-        s = ("%04d-%02d-%02d%c" % (self._year, self._month, self._day, sep) +
+        fmt = "%04d%02d%02d%c" if basic else "%04d-%02d-%02d%c"
+        s = (fmt % (self._year, self._month, self._day, sep) +
              _format_time(self._hour, self._minute, self._second,
-                          self._microsecond, timespec))
+                          self._microsecond, timespec, basic))
 
-        off = self.utcoffset()
-        tz = _format_offset(off)
+        tz = self._tzstr(basic)
         if tz:
             s += tz