Support time zone information in the createDate attribute in the index

.github/requirements.txt

@@ -4,4 +4,5 @@ distutils-pytest
 git-props
 pytest >= 3.6.0
 pytest-dependency
+python-dateutil
 setuptools

CHANGES.rst

@@ -10,6 +10,8 @@ New features
 
 + `#68`_, `#70`_: Extend the index file format to store attributes of
   the index itself.
++ `#7`_, `#67`_: Support time zone information in the `createDate`
+  attribute in the index.
 + `#38`_, `#62`_: Add geo information to the output of the `stats`
   subcommand in :ref:`photo-idx`.
 
@@ -21,15 +23,20 @@ Incompatible changes
   file silently to the new format when writing it back.  But the tools
   from earlier versions will not be able to read the new format.
 
++ Change the argument list for :class:`~photoidx.idxfilter.IdxFilter`
+  and :class:`~photoidx.stats.Stats`: add the idx as new first argument.
+
 Internal changes
 ----------------
 
 + `#66`_: Review build tool chain.
 + `#69`_: Refactor test suite.
 
+.. _#7: https://github.com/RKrahl/photoidx/issues/7
 .. _#38: https://github.com/RKrahl/photoidx/issues/38
 .. _#62: https://github.com/RKrahl/photoidx/pull/62
 .. _#66: https://github.com/RKrahl/photoidx/pull/66
+.. _#67: https://github.com/RKrahl/photoidx/issues/67
 .. _#68: https://github.com/RKrahl/photoidx/issues/68
 .. _#69: https://github.com/RKrahl/photoidx/pull/69
 .. _#70: https://github.com/RKrahl/photoidx/pull/70

README.rst

@@ -36,6 +36,11 @@ Required library packages:
 
 + `ExifRead`_ >= 2.2.0
 
++ `python-dateutil`_
+
+  If this package is not available, the core functions might still
+  work, but some features will be degraded, spurious errors may occur.
+
 + `PySide2`_
 
 Optional library packages:
@@ -147,6 +152,7 @@ permissions and limitations under the License.
 .. _packaging: https://github.com/pypa/packaging/
 .. _PyYAML: https://github.com/yaml/pyyaml
 .. _ExifRead: https://github.com/ianare/exif-py
+.. _python-dateutil: https://dateutil.readthedocs.io/en/stable/
 .. _PySide2: https://www.pyside.org/
 .. _vignette: https://github.com/hydrargyrum/vignette
 .. _Pillow: https://python-pillow.org/

python-photoidx.spec

@@ -18,11 +18,13 @@ BuildRequires:	python3-distutils-pytest
 BuildRequires:	python3-pytest-dependency
 BuildRequires:	python3-PyYAML
 BuildRequires:	python3-ExifRead >= 2.2.0
+BuildRequires:	python3-python-dateutil
 %endif
 Provides:	python3-photo = %{version}-%{release}
 Obsoletes:	python3-photo < %{version}-%{release}
 Requires:	python3-PyYAML
 Requires:	python3-ExifRead >= 2.2.0
+Requires:	python3-python-dateutil
 BuildArch:	noarch
 BuildRoot:	%{_tmppath}/%{name}-%{version}-build
 

scripts/imageview.py

@@ -33,6 +33,6 @@
     else:
         readOnly = not args.create
         dirty = args.create
-idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
+idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
 imageViewer = ImageViewer(idx, idxfilter, args.scale, readOnly, dirty)
 sys.exit(app.exec_())

scripts/photo-idx.py

@@ -1,26 +1,38 @@
 #! /usr/bin/python
 
 import argparse
+from photoidx.datetools import gettz
 import photoidx.index
 import photoidx.idxfilter
 from photoidx.stats import Stats
 
 
 def create(args):
-    checksums = args.checksums.split(',') if args.checksums else []
-    with photoidx.index.Index(idxfile=None, imgdir=args.directory,
-                              checksums=checksums, comment=args.comment) as idx:
+    kwargs = dict(
+        idxfile = None,
+        imgdir = args.directory,
+        checksums = args.checksums.split(',') if args.checksums else [],
+        comment = args.comment,
+        default_tz = args.timezone,
+    )
+    with photoidx.index.Index(**kwargs) as idx:
         idx.write()
 
 def update(args):
-    with photoidx.index.Index(idxfile=args.directory, imgdir=args.directory,
-                              checksums=None, comment=args.comment) as idx:
+    kwargs = dict(
+        idxfile = args.directory,
+        imgdir = args.directory,
+        checksums = None,
+        comment = args.comment,
+        default_tz = args.timezone,
+    )
+    with photoidx.index.Index(**kwargs) as idx:
         idx.write()
 
 def ls(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        for i in idxfilter.filter(idx):
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        for i in idxfilter.filter():
             if args.checksum:
                 try:
                     checksum = i.checksum[args.checksum]
@@ -32,45 +44,45 @@ def ls(args):
 
 def lstags(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
         tags = set()
-        for i in idxfilter.filter(idx):
+        for i in idxfilter.filter():
             tags.update(i.tags)
         for t in sorted(tags):
             print(t)
 
 def addtag(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        for i in idxfilter.filter(idx):
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        for i in idxfilter.filter():
             i.tags.add(args.tag)
         idx.write()
 
 def rmtag(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        for i in idxfilter.filter(idx):
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        for i in idxfilter.filter():
             i.tags.discard(args.tag)
         idx.write()
 
 def select(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        for i in idxfilter.filter(idx):
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        for i in idxfilter.filter():
             i.selected = True
         idx.write()
 
 def deselect(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        for i in idxfilter.filter(idx):
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        for i in idxfilter.filter():
             i.selected = False
         idx.write()
 
 def stats(args):
     with photoidx.index.Index(idxfile=args.directory) as idx:
-        idxfilter = photoidx.idxfilter.IdxFilter.from_args(args)
-        stats = Stats(idxfilter.filter(idx))
+        idxfilter = photoidx.idxfilter.IdxFilter.from_args(idx, args)
+        stats = Stats(idx, idxfilter.filter())
         print(str(stats))
 
 
@@ -81,6 +93,9 @@ def stats(args):
 
 create_parser = subparsers.add_parser('create', help="create the index")
 create_parser.add_argument('--comment', help="Comment text")
+create_parser.add_argument('--timezone',
+                           help="Time zone to set for image create time",
+                           type=gettz, default=gettz())
 create_parser.add_argument('--checksums', default="md5", 
                            help=("comma separated list of "
                                  "hash algorithms to calculate checksums"))
@@ -89,6 +104,9 @@ def stats(args):
 update_parser = subparsers.add_parser('update',
                                       help="add images to an existing index")
 update_parser.add_argument('--comment', help="Comment text")
+update_parser.add_argument('--timezone',
+                           help="Time zone to set for image create time",
+                           type=gettz, default=gettz())
 update_parser.set_defaults(func=update)
 
 ls_parser = subparsers.add_parser('ls', help="list image files")

setup.py

@@ -133,7 +133,7 @@ def run(self):
     python_requires = ">=3.6",
     install_requires = [
         "setuptools", "packaging",
-        "PyYAML >=5.4", "ExifRead >=2.2.0", "PySide2",
+        "PyYAML >=5.4", "ExifRead >=2.2.0", "python-dateutil", "PySide2",
     ],
     cmdclass = dict(cmdclass, build_py=build_py, sdist=sdist, meta=meta),
 )

src/photoidx/datetools.py

@@ -0,0 +1,85 @@
+"""Helper functions for manipulating dates and times.
+
+**Note**: This module might be useful independently of photoidx.  It
+is included here because photoidx uses it internally, but it is not
+considered to be part of the API.  Changes in this module are not
+considered API changes of photoidx.  It may even be removed from
+future versions of the photoidx distribution without further notice.
+"""
+
+import datetime
+from pathlib import Path
+import re
+try:
+    import dateutil.tz
+    _have_dateutil_tz = True
+except ImportError:
+    _have_dateutil_tz = False
+
+_tz_offs_re = re.compile(r'''
+    (?:UTC)?
+    (?P<sign>[+-])
+    (?P<hour>\d{2})
+    :?
+    (?P<min>\d{2})
+''', re.X)
+_tzfile_repr_re = re.compile(r'\w+\(\'(?P<path>[/a-zA-Z0-9_]+)\'\)')
+
+
+def get_rounded_timezone(offs):
+    """Create a timezone object from an offset rounded to whole minutes.
+    """
+    minutes = round(offs.total_seconds()/60)
+    return datetime.timezone(datetime.timedelta(minutes=minutes))
+
+
+def get_local_offset_time_zone():
+    """Get a time zone object corresponding to the local time.
+    """
+    now = datetime.datetime.now()
+    # We'd need utcnow() here, but it is deprecated and will be
+    # removed from future Python versions.
+    utcnow = datetime.datetime.now(datetime.timezone.utc).replace(tzinfo=None)
+    return get_rounded_timezone(now - utcnow)
+
+
+def gettz(name=None):
+    """Get a time zone from a string representation.
+    """
+    if name is not None:
+        if not name:
+            return None
+        m = _tz_offs_re.fullmatch(name)
+        if m:
+            hour, minute = m.group('hour', 'min')
+            offs = datetime.timedelta(hours=int(hour), minutes=int(minute))
+            if m.group('sign') == '-':
+                offs = -offs
+            return datetime.timezone(offs)
+    if _have_dateutil_tz:
+        tz = dateutil.tz.gettz(name)
+        if tz:
+            return tz
+    elif name is None:
+        return get_local_offset_time_zone()
+    raise ValueError("invalid time zone '%s'" % name)
+
+
+def gettz_name(tz):
+    """Get the name from a dateutil.tz.tzfile object.
+
+    This is supposed to be the inverse of gettz().
+    """
+    if _have_dateutil_tz and isinstance(tz, dateutil.tz.tzfile):
+        # Note: this code probably does not work on Windows
+        m = _tzfile_repr_re.match(repr(tz))
+        if m:
+            path = Path(m.group('path')).resolve()
+            for zi_dir in dateutil.tz.TZPATHS:
+                try:
+                    return str(path.relative_to(zi_dir))
+                except ValueError:
+                    continue
+    elif isinstance(tz, datetime.timezone):
+        return str(tz)
+    raise ValueError("invalid time zone object %r" % tz)

src/photoidx/exif.py

@@ -104,6 +104,19 @@ def gpsPosition(self):
             lon = lon_tuple[0] + lon_tuple[1]/60 + lon_tuple[2]/3600
             return { latref:float(lat), lonref:float(lon) }
 
+    @property
+    def gpsDateTime(self):
+        """GPS Date/Time."""
+        try:
+            d = (int(v) for v in self._tags['GPS GPSDate'].values.split(':'))
+            t = (int(v) for v in self._tags['GPS GPSTimeStamp'].values)
+        except (AttributeError, KeyError):
+            return None
+        else:
+            d = datetime.date(*d)
+            t = datetime.time(*t)
+            return datetime.datetime.combine(d, t)
+
     @property
     def cameraModel(self):
         """Camera Model."""

src/photoidx/idxfilter.py

@@ -39,19 +39,28 @@ def _dt(args):
         enddate = _dt(match.group('y1', 'm1', 'd1', 'h1', 'min1', 's1'))
     return (startdate, enddate)
 
+def _set_date_timezone(tz, datetimes):
+    """Replace the time zone in a tuple of datetime objects.
+    """
+    if datetimes:
+        return tuple(dt.replace(tzinfo=tz) for dt in datetimes)
+    else:
+        return None
+
 
 class IdxFilter(object):
 
     @classmethod
-    def from_args(cls, args):
+    def from_args(cls, idx, args):
         kwargs = {}
         for a in ("tags", "select", "date", "gpspos", "gpsradius", "files"):
             kwargs[a] = getattr(args, a)
-        return cls(**kwargs)
+        return cls(idx, **kwargs)
 
-    def __init__(self, 
+    def __init__(self, idx,
                  tags=None, select=None, date=None, 
                  gpspos=None, gpsradius=3.0, files=None):
+        self.idx = idx
         if tags is not None:
             self.taglist = set()
             self.negtaglist = set()
@@ -65,7 +74,7 @@ def __init__(self,
             self.taglist = None
             self.negtaglist = None
         self.select = select
-        self.date = date
+        self.date = _set_date_timezone(self.idx.timeZone, date)
         if gpspos:
             self.gpspos = gpspos
             self.gpsradius = gpsradius
@@ -98,8 +107,8 @@ def __call__(self, item):
                 return False
         return True
 
-    def filter(self, idx):
-        return filter(self, idx)
+    def filter(self):
+        return filter(self, self.idx)
 
 
 def addFilterArguments(argparser):