Add functions to convert timestamp formats

sbws/util/timestamp.py

+"""Util functions to convert between timestamp formats"""
+from datetime import datetime
+
+
+def dt_obj_to_isodt_str(dt):
+    """
+    Convert datetime object to ISO 8601 string.
+
+    :param datetime dt: datetime object in UTC timezone
+    :returns: ISO 8601 string
+    """
+    assert isinstance(dt, datetime)
+    # Using naive datetime object without timezone, assumed utc
+    return dt.replace(microsecond=0).isoformat()
+
+
+def unixts_to_dt_obj(unixts):
+    """
+    Convert unix timestamp to naive datetime object in UTC time zone.
+
+    :param float/int/str unixts: unix timestamp
+    :returns: datetime object in UTC timezone
+    """
+    if isinstance(unixts, str):
+        try:
+            unixts = int(unixts)
+        except ValueError as e:
+            unixts = float(unixts)
+    if isinstance(unixts, float):
+        unixts = int(unixts)
+    assert isinstance(unixts, int)
+    return datetime.utcfromtimestamp(unixts)
+
+
+def unixts_to_isodt_str(unixts):
+    """
+    Convert unix timestamp to ISO 8601 string in UTC time zone.
+
+    :param float/int/str unixts: unix timestamp
+    :returns: ISO 8601 string in UTC time zone
+    """
+    return dt_obj_to_isodt_str(unixts_to_dt_obj(unixts))
+
+
+def now_isodt_str():
+    """Return datetime now as ISO 8601 string in UTC time zone."""
+    return dt_obj_to_isodt_str(datetime.utcnow())
+
+
+def unixts_to_str(unixts):
+    """Convert unix timestamp integer or float to string"""
+    # even if it is only converting to str, ensure that input is nothing else
+    # than int or float
+    assert isinstance(unixts, int) or isinstance(unixts, float)
+    return str(unixts)