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#pylint: disable=invalid-name
import datetime
import re
# python 2.7 backport
if not hasattr(datetime, 'timezone'):
class UTC(datetime.tzinfo):
def utcoffset(self, dt):
return datetime.timedelta(0)
class timezone(object):
utc = UTC()
datetime.timezone = timezone
def valid(s):
return s == 'A'
def timestamp(s):
'''
Converts a timestamp given in "hhmmss[.ss]" ASCII text format to a
datetime.time object
'''
ms_s = s[6:]
ms = ms_s and int(float(ms_s) * 1000000) or 0
t = datetime.time(
hour=int(s[0:2]),
minute=int(s[2:4]),
second=int(s[4:6]),
microsecond=ms,
tzinfo=datetime.timezone.utc)
return t
def datestamp(s):
'''
Converts a datestamp given in "DDMMYY" ASCII text format to a
datetime.datetime object
'''
return datetime.datetime.strptime(s, '%d%m%y').date()
def dm_to_sd(dm):
'''
Converts a geographic co-ordinate given in "degrees/minutes" dddmm.mmmm
format (eg, "12319.943281" = 123 degrees, 19.943281 minutes) to a signed
decimal (python float) format
'''
# '12319.943281'
if not dm or dm == '0':
return 0.
r = re.match(r'^(\d+)(\d\d\.\d+)$', dm)
if not r:
raise ValueError("Geographic coordinate value '{}' is not valid DDDMM.MMM".format(dm))
d, m = r.groups()
return float(d) + float(m) / 60
class LatLonFix(object):
'''Mixin to add `latitude` and `longitude` properties as signed decimals
to NMEA sentences which have co-ordinates given as degrees/minutes (lat, lon)
and cardinal directions (lat_dir, lon_dir)'''
#pylint: disable=no-member
@property
def latitude(self):
'''Latitude in signed degrees (python float)'''
sd = dm_to_sd(self.lat)
if self.lat_dir == 'N':
return +sd
elif self.lat_dir == 'S':
return -sd
else:
return 0.
@property
def longitude(self):
'''Longitude in signed degrees (python float)'''
sd = dm_to_sd(self.lon)
if self.lon_dir == 'E':
return +sd
elif self.lon_dir == 'W':
return -sd
else:
return 0.
@staticmethod
def _minutes(x):
return abs(x * 60.) % 60.
@staticmethod
def _seconds(x):
return abs(x * 3600.) % 60.
@property
def latitude_minutes(self):
return self._minutes(self.latitude)
@property
def longitude_minutes(self):
return self._minutes(self.longitude)
@property
def latitude_seconds(self):
return self._seconds(self.latitude)
@property
def longitude_seconds(self):
return self._seconds(self.longitude)
class DatetimeFix(object):
#pylint: disable=no-member
@property
def datetime(self):
return datetime.datetime.combine(self.datestamp, self.timestamp)
class ValidStatusFix(object):
#pylint: disable=no-member
@property
def is_valid(self):
return self.status == 'A'
class ValidRMCStatusFix(ValidStatusFix):
#pylint: disable=no-member
@property
def is_valid(self):
status = super(ValidRMCStatusFix, self).is_valid
if self.name_to_idx["mode_indicator"] < len(self.data):
status &= self.mode_indicator in tuple('ADEFMPRS')
if self.name_to_idx["nav_status"] < len(self.data):
status &= self.nav_status in tuple('SCU')
return status
class ValidGSAFix(object):
#pylint: disable=no-member
@property
def is_valid(self):
return int(self.mode_fix_type) in [2, 3]
class ValidGGAFix(object):
#pylint: disable=no-member
@property
def is_valid(self):
return self.gps_qual in range(1,6)
class ValidVBWFix(object):
#pylint: disable=no-member
@property
def is_valid(self):
return self.data_validity_water_spd == self.data_validity_grnd_spd == 'A'
class TZInfo(datetime.tzinfo):
def __init__(self, hh, mm):
self.hh = hh
self.mm = mm
super(TZInfo, self).__init__()
def tzname(self, dt):
return ''
def dst(self, dt):
return datetime.timedelta(0)
def utcoffset(self, dt):
return datetime.timedelta(hours=self.hh, minutes=self.mm)
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