Repository: pypa/pipenv

Issue:
Is pulling semver and iso8601 needed?
### Issue description

Is pulling semver and iso8601 needed?


I am going through the list of pipenv dependencies for testing purposes in Fedora. 

When looking for ways to invoke functionalities of the vendored libraries I realized, nothing really imports `semver`. 
`pipenv/vendor/distlib` uses some semver matching, but it has no connection to the actual library.

semver is imported in `tests/test_artifacts/git/pinax/check.py` where it seems it's isolated from the production code - alongside with github3 or tabulate which are also not vendored. I guess (as I don't know the codebase that much) that wherever the artifacts are used, they are isolated and pull the needed libraries from the internet resources.

To check the hypothesis I've removed semver and rerun tests with the same good results as before. 
I assume it may be safely removed, but I may have overlooked something. 

Another thing is bundling iso8601 which is not used anywhere. `pyparsing.py` uses `iso8601_date` and `iso8601_datetime`, but they're defined there, not imported from the library. The whole library seems unused and safe to remove.

If this line of thoughts is correct, I can send a PR with the changes.



Discussion:
@befeleme Your assessment makes sense to me, please feel free to open a PR for this.  

Resolving patch:
diff --git a/pipenv/vendor/iso8601/__init__.py b/pipenv/vendor/iso8601/__init__.py
deleted file mode 100644
--- a/pipenv/vendor/iso8601/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from .iso8601 import *
diff --git a/pipenv/vendor/iso8601/iso8601.py b/pipenv/vendor/iso8601/iso8601.py
deleted file mode 100644
--- a/pipenv/vendor/iso8601/iso8601.py
+++ /dev/null
@@ -1,214 +0,0 @@
-"""ISO 8601 date time string parsing
-
-Basic usage:
->>> import iso8601
->>> iso8601.parse_date("2007-01-25T12:00:00Z")
-datetime.datetime(2007, 1, 25, 12, 0, tzinfo=<iso8601.Utc ...>)
->>>
-
-"""
-
-import datetime
-from decimal import Decimal
-import sys
-import re
-
-__all__ = ["parse_date", "ParseError", "UTC",
-           "FixedOffset"]
-
-if sys.version_info >= (3, 0, 0):
-    _basestring = str
-else:
-    _basestring = basestring
-
-
-# Adapted from http://delete.me.uk/2005/03/iso8601.html
-ISO8601_REGEX = re.compile(
-    r"""
-    (?P<year>[0-9]{4})
-    (
-        (
-            (-(?P<monthdash>[0-9]{1,2}))
-            |
-            (?P<month>[0-9]{2})
-            (?!$)  # Don't allow YYYYMM
-        )
-        (
-            (
-                (-(?P<daydash>[0-9]{1,2}))
-                |
-                (?P<day>[0-9]{2})
-            )
-            (
-                (
-                    (?P<separator>[ T])
-                    (?P<hour>[0-9]{2})
-                    (:{0,1}(?P<minute>[0-9]{2})){0,1}
-                    (
-                        :{0,1}(?P<second>[0-9]{1,2})
-                        ([.,](?P<second_fraction>[0-9]+)){0,1}
-                    ){0,1}
-                    (?P<timezone>
-                        Z
-                        |
-                        (
-                            (?P<tz_sign>[-+])
-                            (?P<tz_hour>[0-9]{2})
-                            :{0,1}
-                            (?P<tz_minute>[0-9]{2}){0,1}
-                        )
-                    ){0,1}
-                ){0,1}
-            )
-        ){0,1}  # YYYY-MM
-    ){0,1}  # YYYY only
-    $
-    """,
-    re.VERBOSE
-)
-
-class ParseError(ValueError):
-    """Raised when there is a problem parsing a date string"""
-
-if sys.version_info >= (3, 2, 0):
-    UTC = datetime.timezone.utc
-    def FixedOffset(offset_hours, offset_minutes, name):
-        return datetime.timezone(
-            datetime.timedelta(
-                hours=offset_hours, minutes=offset_minutes),
-            name)
-else:
-    # Yoinked from python docs
-    ZERO = datetime.timedelta(0)
-    class Utc(datetime.tzinfo):
-        """UTC Timezone
-
-        """
-        def utcoffset(self, dt):
-            return ZERO
-
-        def tzname(self, dt):
-            return "UTC"
-
-        def dst(self, dt):
-            return ZERO
-
-        def __repr__(self):
-            return "<iso8601.Utc>"
-
-    UTC = Utc()
-
-    class FixedOffset(datetime.tzinfo):
-        """Fixed offset in hours and minutes from UTC
-
-        """
-        def __init__(self, offset_hours, offset_minutes, name):
-            self.__offset_hours = offset_hours  # Keep for later __getinitargs__
-            self.__offset_minutes = offset_minutes  # Keep for later __getinitargs__
-            self.__offset = datetime.timedelta(
-                hours=offset_hours, minutes=offset_minutes)
-            self.__name = name
-
-        def __eq__(self, other):
-            if isinstance(other, FixedOffset):
-                return (
-                    (other.__offset == self.__offset)
-                    and
-                    (other.__name == self.__name)
-                )
-            return NotImplemented
-
-        def __getinitargs__(self):
-            return (self.__offset_hours, self.__offset_minutes, self.__name)
-
-        def utcoffset(self, dt):
-            return self.__offset
-
-        def tzname(self, dt):
-            return self.__name
-
-        def dst(self, dt):
-            return ZERO
-
-        def __repr__(self):
-            return "<FixedOffset %r %r>" % (self.__name, self.__offset)
-
-
-def to_int(d, key, default_to_zero=False, default=None, required=True):
-    """Pull a value from the dict and convert to int
-
-    :param default_to_zero: If the value is None or empty, treat it as zero
-    :param default: If the value is missing in the dict use this default
-
-    """
-    value = d.get(key) or default
-    if (value in ["", None]) and default_to_zero:
-        return 0
-    if value is None:
-        if required:
-            raise ParseError("Unable to read %s from %s" % (key, d))
-    else:
-        return int(value)
-
-def parse_timezone(matches, default_timezone=UTC):
-    """Parses ISO 8601 time zone specs into tzinfo offsets
-
-    """
-
-    if matches["timezone"] == "Z":
-        return UTC
-    # This isn't strictly correct, but it's common to encounter dates without
-    # timezones so I'll assume the default (which defaults to UTC).
-    # Addresses issue 4.
-    if matches["timezone"] is None:
-        return default_timezone
-    sign = matches["tz_sign"]
-    hours = to_int(matches, "tz_hour")
-    minutes = to_int(matches, "tz_minute", default_to_zero=True)
-    description = "%s%02d:%02d" % (sign, hours, minutes)
-    if sign == "-":
-        hours = -hours
-        minutes = -minutes
-    return FixedOffset(hours, minutes, description)
-
-def parse_date(datestring, default_timezone=UTC):
-    """Parses ISO 8601 dates into datetime objects
-
-    The timezone is parsed from the date string. However it is quite common to
-    have dates without a timezone (not strictly correct). In this case the
-    default timezone specified in default_timezone is used. This is UTC by
-    default.
-
-    :param datestring: The date to parse as a string
-    :param default_timezone: A datetime tzinfo instance to use when no timezone
-                             is specified in the datestring. If this is set to
-                             None then a naive datetime object is returned.
-    :returns: A datetime.datetime instance
-    :raises: ParseError when there is a problem parsing the date or
-             constructing the datetime instance.
-
-    """
-    if not isinstance(datestring, _basestring):
-        raise ParseError("Expecting a string %r" % datestring)
-    m = ISO8601_REGEX.match(datestring)
-    if not m:
-        raise ParseError("Unable to parse date string %r" % datestring)
-    groups = m.groupdict()
-
-    tz = parse_timezone(groups, default_timezone=default_timezone)
-
-    groups["second_fraction"] = int(Decimal("0.%s" % (groups["second_fraction"] or 0)) * Decimal("1000000.0"))
-
-    try:
-        return datetime.datetime(
-            year=to_int(groups, "year"),
-            month=to_int(groups, "month", default=to_int(groups, "monthdash", required=False, default=1)),
-            day=to_int(groups, "day", default=to_int(groups, "daydash", required=False, default=1)),
-            hour=to_int(groups, "hour", default_to_zero=True),
-            minute=to_int(groups, "minute", default_to_zero=True),
-            second=to_int(groups, "second", default_to_zero=True),
-            microsecond=groups["second_fraction"],
-            tzinfo=tz,
-        )
-    except Exception as e:
-        raise ParseError(e)


Test patch:
diff --git a/pipenv/vendor/iso8601/test_iso8601.py b/pipenv/vendor/iso8601/test_iso8601.py
deleted file mode 100644
--- a/pipenv/vendor/iso8601/test_iso8601.py
+++ /dev/null
@@ -1,102 +0,0 @@
-# coding=UTF-8
-from __future__ import absolute_import
-
-import copy
-import datetime
-import pickle
-
-import pytest
-
-from pipenv.vendor.iso8601 import iso8601
-
-def test_iso8601_regex():
-    assert iso8601.ISO8601_REGEX.match("2006-10-11T00:14:33Z")
-
-def test_fixedoffset_eq():
-    # See https://bitbucket.org/micktwomey/pyiso8601/issues/19
-    datetime.tzinfo() == iso8601.FixedOffset(2, 0, '+2:00')
-
-def test_parse_no_timezone_different_default():
-    tz = iso8601.FixedOffset(2, 0, "test offset")
-    d = iso8601.parse_date("2007-01-01T08:00:00", default_timezone=tz)
-    assert d == datetime.datetime(2007, 1, 1, 8, 0, 0, 0, tz)
-    assert d.tzinfo == tz
-
-def test_parse_utc_different_default():
-    """Z should mean 'UTC', not 'default'.
-
-    """
-    tz = iso8601.FixedOffset(2, 0, "test offset")
-    d = iso8601.parse_date("2007-01-01T08:00:00Z", default_timezone=tz)
-    assert d == datetime.datetime(2007, 1, 1, 8, 0, 0, 0, iso8601.UTC)
-
-@pytest.mark.parametrize("invalid_date, error_string", [
-    ("2013-10-", "Unable to parse date string"),
-    ("2013-", "Unable to parse date string"),
-    ("", "Unable to parse date string"),
-    (None, "Expecting a string"),
-    ("wibble", "Unable to parse date string"),
-    ("23", "Unable to parse date string"),
-    ("131015T142533Z", "Unable to parse date string"),
-    ("131015", "Unable to parse date string"),
-    ("20141", "Unable to parse date string"),
-    ("201402", "Unable to parse date string"),
-    ("2007-06-23X06:40:34.00Z", "Unable to parse date string"),  # https://code.google.com/p/pyiso8601/issues/detail?id=14
-    ("2007-06-23 06:40:34.00Zrubbish", "Unable to parse date string"),  # https://code.google.com/p/pyiso8601/issues/detail?id=14
-    ("20114-01-03T01:45:49", "Unable to parse date string"),
-])
-def test_parse_invalid_date(invalid_date, error_string):
-    assert isinstance(invalid_date, str) or invalid_date is None  # Why? 'cos I've screwed up the parametrize before :)
-    with pytest.raises(iso8601.ParseError) as exc:
-        iso8601.parse_date(invalid_date)
-    assert exc.errisinstance(iso8601.ParseError)
-    assert str(exc.value).startswith(error_string)
-
-@pytest.mark.parametrize("valid_date,expected_datetime,isoformat", [
-    ("2007-06-23 06:40:34.00Z", datetime.datetime(2007, 6, 23, 6, 40, 34, 0, iso8601.UTC), "2007-06-23T06:40:34+00:00"),  # Handle a separator other than T
-    ("1997-07-16T19:20+01:00", datetime.datetime(1997, 7, 16, 19, 20, 0, 0, iso8601.FixedOffset(1, 0, "+01:00")), "1997-07-16T19:20:00+01:00"),  # Parse with no seconds
-    ("2007-01-01T08:00:00", datetime.datetime(2007, 1, 1, 8, 0, 0, 0, iso8601.UTC), "2007-01-01T08:00:00+00:00"),  # Handle timezone-less dates. Assumes UTC. http://code.google.com/p/pyiso8601/issues/detail?id=4
-    ("2006-10-20T15:34:56.123+02:30", datetime.datetime(2006, 10, 20, 15, 34, 56, 123000, iso8601.FixedOffset(2, 30, "+02:30")), None),
-    ("2006-10-20T15:34:56Z", datetime.datetime(2006, 10, 20, 15, 34, 56, 0, iso8601.UTC), "2006-10-20T15:34:56+00:00"),
-    ("2007-5-7T11:43:55.328Z", datetime.datetime(2007, 5, 7, 11, 43, 55, 328000, iso8601.UTC), "2007-05-07T11:43:55.328000+00:00"),  # http://code.google.com/p/pyiso8601/issues/detail?id=6
-    ("2006-10-20T15:34:56.123Z", datetime.datetime(2006, 10, 20, 15, 34, 56, 123000, iso8601.UTC), "2006-10-20T15:34:56.123000+00:00"),
-    ("2013-10-15T18:30Z", datetime.datetime(2013, 10, 15, 18, 30, 0, 0, iso8601.UTC), "2013-10-15T18:30:00+00:00"),
-    ("2013-10-15T22:30+04", datetime.datetime(2013, 10, 15, 22, 30, 0, 0, iso8601.FixedOffset(4, 0, "+04:00")), "2013-10-15T22:30:00+04:00"),  # <time>±hh:mm
-    ("2013-10-15T1130-0700", datetime.datetime(2013, 10, 15, 11, 30, 0, 0, iso8601.FixedOffset(-7, 0, "-07:00")), "2013-10-15T11:30:00-07:00"),  # <time>±hhmm
-    ("2013-10-15T1130+0700", datetime.datetime(2013, 10, 15, 11, 30, 0, 0, iso8601.FixedOffset(+7, 0, "+07:00")), "2013-10-15T11:30:00+07:00"),  # <time>±hhmm
-    ("2013-10-15T1130+07", datetime.datetime(2013, 10, 15, 11, 30, 0, 0, iso8601.FixedOffset(+7, 0, "+07:00")), "2013-10-15T11:30:00+07:00"),  # <time>±hh
-    ("2013-10-15T1130-07", datetime.datetime(2013, 10, 15, 11, 30, 0, 0, iso8601.FixedOffset(-7, 0, "-07:00")), "2013-10-15T11:30:00-07:00"),  # <time>±hh
-    ("2013-10-15T15:00-03:30", datetime.datetime(2013, 10, 15, 15, 0, 0, 0, iso8601.FixedOffset(-3, -30, "-03:30")), "2013-10-15T15:00:00-03:30"),
-    ("2013-10-15T183123Z", datetime.datetime(2013, 10, 15, 18, 31, 23, 0, iso8601.UTC), "2013-10-15T18:31:23+00:00"),  # hhmmss
-    ("2013-10-15T1831Z", datetime.datetime(2013, 10, 15, 18, 31, 0, 0, iso8601.UTC), "2013-10-15T18:31:00+00:00"),  # hhmm
-    ("2013-10-15T18Z", datetime.datetime(2013, 10, 15, 18, 0, 0, 0, iso8601.UTC), "2013-10-15T18:00:00+00:00"),  # hh
-    ("2013-10-15", datetime.datetime(2013, 10, 15, 0, 0, 0, 0, iso8601.UTC), "2013-10-15T00:00:00+00:00"),  # YYYY-MM-DD
-    ("20131015T18:30Z", datetime.datetime(2013, 10, 15, 18, 30, 0, 0, iso8601.UTC), "2013-10-15T18:30:00+00:00"),  # YYYYMMDD
-    ("2012-12-19T23:21:28.512400+00:00", datetime.datetime(2012, 12, 19, 23, 21, 28, 512400, iso8601.FixedOffset(0, 0, "+00:00")), "2012-12-19T23:21:28.512400+00:00"),  # https://code.google.com/p/pyiso8601/issues/detail?id=21
-    ("2006-10-20T15:34:56.123+0230", datetime.datetime(2006, 10, 20, 15, 34, 56, 123000, iso8601.FixedOffset(2, 30, "+02:30")), "2006-10-20T15:34:56.123000+02:30"),  # https://code.google.com/p/pyiso8601/issues/detail?id=18
-    ("19950204", datetime.datetime(1995, 2, 4, tzinfo=iso8601.UTC), "1995-02-04T00:00:00+00:00"),  # https://code.google.com/p/pyiso8601/issues/detail?id=1
-    ("2010-07-20 15:25:52.520701+00:00", datetime.datetime(2010, 7, 20, 15, 25, 52, 520701, iso8601.FixedOffset(0, 0, "+00:00")), "2010-07-20T15:25:52.520701+00:00"),  # https://code.google.com/p/pyiso8601/issues/detail?id=17
-    ("2010-06-12", datetime.datetime(2010, 6, 12, tzinfo=iso8601.UTC), "2010-06-12T00:00:00+00:00"),  # https://code.google.com/p/pyiso8601/issues/detail?id=16
-    ("1985-04-12T23:20:50.52-05:30", datetime.datetime(1985, 4, 12, 23, 20, 50, 520000, iso8601.FixedOffset(-5, -30, "-05:30")), "1985-04-12T23:20:50.520000-05:30"),  # https://bitbucket.org/micktwomey/pyiso8601/issue/8/015-parses-negative-timezones-incorrectly
-    ("1997-08-29T06:14:00.000123Z", datetime.datetime(1997, 8, 29, 6, 14, 0, 123, iso8601.UTC), "1997-08-29T06:14:00.000123+00:00"),  # https://bitbucket.org/micktwomey/pyiso8601/issue/9/regression-parsing-microseconds
-    ("2014-02", datetime.datetime(2014, 2, 1, 0, 0, 0, 0, iso8601.UTC), "2014-02-01T00:00:00+00:00"),  # https://bitbucket.org/micktwomey/pyiso8601/issue/14/regression-yyyy-mm-no-longer-parses
-    ("2014", datetime.datetime(2014, 1, 1, 0, 0, 0, 0, iso8601.UTC), "2014-01-01T00:00:00+00:00"),  # YYYY
-    ("1997-08-29T06:14:00,000123Z", datetime.datetime(1997, 8, 29, 6, 14, 0, 123, iso8601.UTC), "1997-08-29T06:14:00.000123+00:00"),  # Use , as decimal separator
-])
-def test_parse_valid_date(valid_date, expected_datetime, isoformat):
-    parsed = iso8601.parse_date(valid_date)
-    assert parsed.year == expected_datetime.year
-    assert parsed.month == expected_datetime.month
-    assert parsed.day == expected_datetime.day
-    assert parsed.hour == expected_datetime.hour
-    assert parsed.minute == expected_datetime.minute
-    assert parsed.second == expected_datetime.second
-    assert parsed.microsecond == expected_datetime.microsecond
-    assert parsed.tzinfo == expected_datetime.tzinfo
-    assert parsed == expected_datetime
-    assert parsed.isoformat() == expected_datetime.isoformat()
-    copy.deepcopy(parsed)  # ensure it's deep copy-able
-    pickle.dumps(parsed)  # ensure it pickles
-    if isoformat:
-        assert parsed.isoformat() == isoformat
-    assert iso8601.parse_date(parsed.isoformat()) == parsed  # Test round trip