Mode() function error's Traceback shows `xrange()` being called by statistics module when using Python3.7

Question

I'm writing a program in Python3.7 and using the statistics module for the mode() (and more) function. Why is the statistics module in Python3 calling xrange() when that function doesn't exist in Python3? Is this a bug? I don't think it is because this code worked for me before (I think I was using Python3.7 then too).

Error: NameError: name 'xrange' is not defined

Relavant code:

    def mode_tags(self):
        self._mode_tags = mode(self._tags_dict.values())
        return self._mode_tags

Code referenced from statistics module:

  430     # Generate a table of sorted (value, frequency) pairs.
--> 431     table = _counts(data)
    432     if len(table) == 1:
    433         return table[0][0]

    263     # Extract the values with the highest frequency.
    264     maxfreq = table[0][1]
--> 265     for i in xrange(1, len(table)):
    266         if table[i][1] != maxfreq:
    267             table = table[:i]

---

Edit:

I figured out it has something to do with my pipvenv as the code works fine outside on the host environment.

Pipfile:

[[source]]
name = "pypi"
url = "https://pypi.org/simple"
verify_ssl = true

[dev-packages]
pysnooper = "*"

[packages]
statistics = "*"

[requires]

Pipefile.lock:

{
    "_meta": {
        "hash": {
            "sha256": "bfce8912bf5c44526c839affc414f071feb36b57777765d1415f10a78d2e3aba"
        },
        "pipfile-spec": 6,
        "requires": {
            "python_version": "3.7"
        },
        "sources": [
            {
                "name": "pypi",
                "url": "https://pypi.org/simple",
                "verify_ssl": true
            }
        ]
    },
    "default": {
        "docutils": {
            "hashes": [
                "sha256:6c4f696463b79f1fb8ba0c594b63840ebd41f059e92b31957c46b74a4599b6d0",
                "sha256:9e4d7ecfc600058e07ba661411a2b7de2fd0fafa17d1a7f7361cd47b1175c827",
                "sha256:a2aeea129088da402665e92e0b25b04b073c04b2dce4ab65caaa38b7ce2e1a99"
            ],
            "version": "==0.15.2"
        },
        "statistics": {
            "hashes": [
                "sha256:2dc379b80b07bf2ddd5488cad06b2b9531da4dd31edb04dc9ec0dc226486c138"
            ],
            "index": "pypi",
            "version": "==1.0.3.5"
        }
    },
    "develop": {
        "pysnooper": {
            "hashes": [
                "sha256:7d7684d9d5cf1d026bba6a52e87009eab9458d3265b13059ab1abaea7eee6c93",
                "sha256:85892ef6f4009af7d729e73c7b9e4071a16d5063b1ac9340741c5f192501441b"
            ],
            "index": "pypi",
            "version": "==0.3.0"
        }
    }
}