AttributeError: module 'jsonschema' has no attribute 'Draft7Validator'

Please help. I have no idea how to fix this :(

import altair as alt causes the following

<ipython-input-4-8ce2321ae70f> in <module>()
      1 import pandas as pd
----> 2 import altair as alt

~\altair\__init__.py in <module>()
      2 __version__ = "4.2.0.dev0"
      3 
----> 4 from .vegalite import *
      5 from . import examples
      6 

~\altair\vegalite\__init__.py in <module>()
      1 # flake8: noqa
----> 2 from .v4 import *

~\altair\vegalite\v4\__init__.py in <module>()
      1 # flake8: noqa
----> 2 from .schema import *
      3 from .api import *
      4 
      5 from ...datasets import list_datasets, load_dataset

~\altair\vegalite\v4\schema\__init__.py in <module>()
      1 # flake8: noqa
----> 2 from .core import *
      3 from .channels import *
      4 SCHEMA_VERSION = 'v4.17.0'
      5 SCHEMA_URL = 'https://vega.github.io/schema/vega-lite/v4.17.0.json'

~\altair\vegalite\v4\schema\core.py in <module>()
      2 # tools/generate_schema_wrapper.py. Do not modify directly.
      3 
----> 4 from altair.utils.schemapi import SchemaBase, Undefined, _subclasses
      5 
      6 import pkgutil

~\altair\utils\__init__.py in <module>()
----> 1 from .core import (
      2     infer_vegalite_type,
      3     infer_encoding_types,
      4     sanitize_dataframe,
      5     parse_shorthand,

~\altair\utils\core.py in <module>()
     15 import numpy as np
     16 
---> 17 from .schemapi import SchemaBase, Undefined
     18 
     19 try:

~\altair\utils\schemapi.py in <module>()
    141 
    142 
--> 143 class SchemaBase(object):
    144     """Base class for schema wrappers.
    145 

~\altair\utils\schemapi.py in SchemaBase()
    151     _rootschema = None
    152     _class_is_valid_at_instantiation = True
--> 153     _validator = jsonschema.Draft7Validator
    154 
    155     def __init__(self, *args, **kwds):

AttributeError: module 'jsonschema' has no attribute 'Draft7Validator'```