diff --git a/followthemoney/export/common.py b/followthemoney/export/common.py
index 2852ab8e2..5e43f57d0 100644
--- a/followthemoney/export/common.py
+++ b/followthemoney/export/common.py
@@ -23,7 +23,7 @@ def exportable_fields(
             yield prop, proxy.get(prop)
 
     def write(self, proxy: E, extra: Optional[List[str]] = None) -> None:
-        raise NotImplemented
+        raise NotImplementedError
 
     def finalize(self) -> None:
         pass
diff --git a/followthemoney/export/excel.py b/followthemoney/export/excel.py
index 2d39751b7..a627c4cb1 100644
--- a/followthemoney/export/excel.py
+++ b/followthemoney/export/excel.py
@@ -61,7 +61,7 @@ def write(self, proxy: E, extra: Optional[List[str]] = None) -> None:
                 headers.append(prop.label)
             sheet = self.make_sheet(proxy.schema.plural, headers)
             self.sheets[proxy.schema] = sheet
-        sheet = self.sheets.get(proxy.schema)
+        sheet = self.sheets[proxy.schema]
         try:
             cells = [proxy.id]
             cells.extend(extra or [])
diff --git a/followthemoney/export/rdf.py b/followthemoney/export/rdf.py
index 3265b58cb..196638da9 100644
--- a/followthemoney/export/rdf.py
+++ b/followthemoney/export/rdf.py
@@ -1,6 +1,6 @@
 import logging
-from typing import List, Optional, TextIO
 from rdflib import Graph
+from typing import List, Optional, TextIO
 
 from followthemoney.export.common import Exporter
 from followthemoney.proxy import E
diff --git a/followthemoney/mapping/csv.py b/followthemoney/mapping/csv.py
index 4df1a86b3..e4402a605 100644
--- a/followthemoney/mapping/csv.py
+++ b/followthemoney/mapping/csv.py
@@ -5,7 +5,7 @@
 import requests
 from csv import DictReader
 from urllib.parse import urlparse
-from banal import keys_values, is_listish
+from banal import keys_values
 from typing import (
     TYPE_CHECKING,
     Any,
diff --git a/followthemoney/mapping/entity.py b/followthemoney/mapping/entity.py
index 9ac37f882..f2754787b 100644
--- a/followthemoney/mapping/entity.py
+++ b/followthemoney/mapping/entity.py
@@ -9,7 +9,7 @@
 from followthemoney.proxy import EntityProxy
 from followthemoney.mapping.property import PropertyMapping
 from followthemoney.mapping.source import Record
-from followthemoney.exc import InvalidData, InvalidMapping
+from followthemoney.exc import InvalidMapping
 
 if TYPE_CHECKING:
     from followthemoney.model import Model
diff --git a/followthemoney/mapping/property.py b/followthemoney/mapping/property.py
index 0f9efb2b0..1cd76f3cf 100644
--- a/followthemoney/mapping/property.py
+++ b/followthemoney/mapping/property.py
@@ -8,7 +8,7 @@
 from followthemoney.helpers import inline_names
 from followthemoney.exc import InvalidMapping
 from followthemoney.proxy import EntityProxy
-from followthemoney.util import get_entity_id, sanitize_text
+from followthemoney.util import sanitize_text
 from followthemoney.property import Property
 from followthemoney.mapping.source import Record
 
diff --git a/followthemoney/mapping/source.py b/followthemoney/mapping/source.py
index 187e6d52f..4c1a854a9 100644
--- a/followthemoney/mapping/source.py
+++ b/followthemoney/mapping/source.py
@@ -15,7 +15,7 @@ def __init__(self, query: "QueryMapping", data: Dict[str, Any]) -> None:
 
     @property
     def records(self) -> Generator[Record, None, None]:
-        raise NotImplemented
+        raise NotImplementedError
 
     def __len__(self) -> int:
         return 0
diff --git a/followthemoney/messages.py b/followthemoney/messages.py
index 2bf497e42..d939ebbcc 100644
--- a/followthemoney/messages.py
+++ b/followthemoney/messages.py
@@ -1,5 +1,5 @@
 import yaml
-from typing import Any, Dict, Generator, List, TextIO, Tuple, Union
+from typing import Any, Dict, Generator, List, TextIO, Tuple
 
 Message = Tuple[Any, Any, List[str], List[str]]
 
diff --git a/followthemoney/namespace.py b/followthemoney/namespace.py
index 9e1cbf1d7..391cf6a68 100644
--- a/followthemoney/namespace.py
+++ b/followthemoney/namespace.py
@@ -23,7 +23,7 @@
 the server without compromising isolation.
 """
 import hmac
-from typing import Any, Optional, Tuple, Union, TypeVar
+from typing import Any, Optional, Tuple, Union
 
 from followthemoney.types import registry
 from followthemoney.proxy import E
diff --git a/followthemoney/types/__init__.py b/followthemoney/types/__init__.py
index 73e460bc7..d306bd4a4 100644
--- a/followthemoney/types/__init__.py
+++ b/followthemoney/types/__init__.py
@@ -22,7 +22,6 @@
 from followthemoney.types.number import NumberType
 from followthemoney.types.common import PropertyType
 
-
 registry = Registry()
 registry.add(UrlType)
 registry.add(NameType)
@@ -45,3 +44,5 @@
 registry.add(HTMLType)
 registry.add(StringType)
 registry.add(NumberType)
+
+__all__ = ["PropertyType", "registry"]
diff --git a/followthemoney/types/identifier.py b/followthemoney/types/identifier.py
index 5aacaf075..24878e987 100644
--- a/followthemoney/types/identifier.py
+++ b/followthemoney/types/identifier.py
@@ -1,5 +1,4 @@
 import re
-from typing import Callable, Sequence
 
 from followthemoney.types.common import PropertyType
 from followthemoney.util import dampen, shortest, longest