diff --git a/tests/test_file.py b/tests/test_file.py
index 93eb6f5af07a433199141fbd98ca429b1626ea72..1a7513c2ecddb0a78f3fe8ccb5b2b5af5886b72c 100644
--- a/tests/test_file.py
+++ b/tests/test_file.py
@@ -5,8 +5,9 @@
 #
 # Copyright (C) 2018 Research Group Biomedical Physics,
 # Max-Planck-Institute for Dynamics and Self-Organization Göttingen
-# Copyright (C) 2019 IndiScale GmbH (info@indiscale.com)
-# Copyright (C) 2019 Daniel Hornung (d.hornung@indiscale.com)
+# Copyright (C) 2019-2020 IndiScale GmbH <info@indiscale.com>
+# Copyright (C) 2019 Daniel Hornung <d.hornung@indiscale.com>
+# Copyright (C) 2020 Timm Fitschen <t.fitschen@indiscale.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
@@ -34,9 +35,6 @@ from sys import maxsize as maxint
 
 from lxml import etree
 from pytest import raises, mark
-from nose.tools import (assert_equal, assert_false,  # @UnresolvedImport
-                        assert_is_not_none, assert_raises, assert_true,
-                        nottest)
 
 from caosdb import Info
 from caosdb import administration as admin
@@ -86,8 +84,8 @@ def test_file_with_space():
                         file="test.dat")
     file_.insert()
     qfile = execute_query("FIND FILE TestFile", unique=True)
-    assert_equal(qfile.id, file_.id)
-    assert_equal(qfile.path, "/testfiles/test file with spaces.dat")
+    assert qfile.id == file_.id
+    assert qfile.path == "/testfiles/test file with spaces.dat"
 
     qfile.download("test2.dat")
 
@@ -108,7 +106,7 @@ def test_pickup_file():
                             hex(randint(0, maxint)),
                             pickup="testpickup.dat")
         file_.insert()
-        assert_is_not_none(file_.id)
+        assert file_.id is not None
 
 
 def test_pickup_folder():
@@ -162,8 +160,8 @@ def test_file4():
             c = models.Container()
             c.extend([file1_, file2_])
             c.insert()
-            assert_is_not_none(file1_.id)
-            assert_is_not_none(file2_.id)
+            assert file1_.id is not None
+            assert file2_.id is not None
     finally:
         try:
             c.delete()
@@ -186,8 +184,8 @@ def test_upload_complete_folder():
     c = models.Container()
     c.extend([file1_, file2_])
     c.insert()
-    assert_is_not_none(file1_.id)
-    assert_is_not_none(file2_.id)
+    assert file1_.id is not None
+    assert file2_.id is not None
     c.delete()
 
     c = models.Container()
@@ -198,7 +196,7 @@ def test_upload_complete_folder():
                           file="testfolder")
     c.append(folder_)
     c.insert()
-    assert_is_not_none(folder_.id)
+    assert folder_.id is not None
     c.delete()
 
 
@@ -275,8 +273,8 @@ def test_file7():
                             file="test.dat")
         file_.insert()
 
-        assert_is_not_none(file_.id)
-        assert_true(file_.is_valid())
+        assert file_.id is not None
+        assert file_.is_valid() is True
 
         # pickup_folder
         # and try to store it to testfiles2/
@@ -302,7 +300,8 @@ def test_file7():
                 path="testfiles2/",
                 pickup="path")
 
-            assert_raises(EntityError, folder_.insert)
+            with raises(EntityError):
+                folder_.insert
     finally:
         try:
             folder_.delete()
@@ -470,20 +469,20 @@ def test_insert_files_in_dir_error1():
             "InsertFilesInDir": "/root"})
     # If this fails, it is likely that the server runs with root permissions
     # which is discouraged.
-    assert_is_not_none(c.messages["Error", 0])
-    assert_true(c.messages["Error", 0][0].startswith(
-        "Cannot read or enter the desired directory."))
+    assert c.messages["Error", 0] is not None
+    assert c.messages["Error", 0][0].startswith(
+        "Cannot read or enter the desired directory.") is True
 
     c = models.Container()
     c.retrieve(unique=False, raise_exception_on_error=False,
                flags={"InsertFilesInDir": "non-existent"})
-    assert_is_not_none(c.messages["Error", 0])
-    assert_true(c.messages["Error", 0][0].startswith("No such directory"))
+    assert c.messages["Error", 0] is not None
+    assert c.messages["Error", 0][0].startswith("No such directory") is True
 
     c.insert(raise_exception_on_error=False, flags={
              "InsertFilesInDir": "non-existent"})
-    assert_is_not_none(c.messages["Error", 0])
-    assert_true(c.messages["Error", 0][0].startswith("No such directory"))
+    assert c.messages["Error", 0] is not None
+    assert c.messages["Error", 0][0].startswith("No such directory") is True
 
     c = models.Container()
     c.retrieve(
@@ -491,8 +490,8 @@ def test_insert_files_in_dir_error1():
         raise_exception_on_error=False,
         flags={
             "InsertFilesInDir": "."})
-    assert_is_not_none(c.messages["Error", 0])
-    assert_true(c.messages["Error", 0][0].startswith("Dir is not allowed"))
+    assert c.messages["Error", 0] is not None
+    assert c.messages["Error", 0][0].startswith("Dir is not allowed") is True
 
 
 def test_insert_files_in_dir_with_symlink():
@@ -522,10 +521,10 @@ def test_insert_files_in_dir_with_symlink():
             flags={
                 "InsertFilesInDir": path_on_server +
                 "linked_subfolder"})
-        assert_is_not_none(c.messages["Warning", 6])
-        assert_equal(c.messages["Warning", 6][0],
-                     "Directory or file is symbolic link: " + path_on_server +
-                     "linked_subfolder")
+        assert c.messages["Warning", 6] is not None
+        assert c.messages["Warning", 6][0] == ("Directory or file is symbolic "
+                                               "link: {}linked_subfolder"
+                                               ).format(path_on_server)
 
         c = models.Container()
         c.retrieve(
@@ -535,11 +534,11 @@ def test_insert_files_in_dir_with_symlink():
                 "InsertFilesInDir": "--force-allow-symlinks " +
                 path_on_server +
                 "linked_subfolder"})
-        assert_is_not_none(c.messages["Info", 0])
-        assert_equal(c.messages["Info", 0][0],
-                     "Files count in linked_subfolder/: 1")
-        assert_equal(c[0].name, "test2.dat")
-        assert_equal(c[0].path, "/linked_subfolder/test2.dat")
+        assert c.messages["Info", 0] is not None
+        assert c.messages["Info",
+                          0][0] == "Files count in linked_subfolder/: 1"
+        assert c[0].name == "test2.dat"
+        assert c[0].path == "/linked_subfolder/test2.dat"
 
         d = models.Container()
         d.insert(
@@ -549,12 +548,12 @@ def test_insert_files_in_dir_with_symlink():
                 "InsertFilesInDir": "--force-allow-symlinks " +
                 path_on_server +
                 "linked_subfolder"})
-        assert_is_not_none(c.messages["Info", 0])
-        assert_equal(d.messages["Info", 0][0],
-                     "Files count in linked_subfolder/: 1")
-        assert_true(d[0].is_valid())
-        assert_equal(d[0].name, "test2.dat")
-        assert_equal(d[0].path, "/linked_subfolder/test2.dat")
+        assert c.messages["Info", 0] is not None
+        assert d.messages["Info",
+                          0][0] == "Files count in linked_subfolder/: 1"
+        assert d[0].is_valid() is True
+        assert d[0].name == "test2.dat"
+        assert d[0].path == "/linked_subfolder/test2.dat"
 
     finally:
         try:
@@ -599,9 +598,8 @@ def test_insert_files_in_dir():
             raise_exception_on_error=False,
             flags={
                 "InsertFilesInDir": path_on_server})
-        assert_is_not_none(c.messages["Info", 0])
-        assert_equal(c.messages["Info", 0][0],
-                     "Files count in testfolder/: 2")
+        assert c.messages["Info", 0] is not None
+        assert c.messages["Info", 0][0] == "Files count in testfolder/: 2"
 
         # ACTUAL RUN
         d = models.Container()
@@ -610,10 +608,9 @@ def test_insert_files_in_dir():
             raise_exception_on_error=False,
             flags={
                 "InsertFilesInDir": path_on_server})
-        assert_is_not_none(c.messages["Info", 0])
-        assert_equal(d.messages["Info", 0][0],
-                     "Files count in testfolder/: 2")
-        assert_true(d[0].is_valid())
+        assert c.messages["Info", 0] is not None
+        assert d.messages["Info", 0][0] == "Files count in testfolder/: 2"
+        assert d[0].is_valid() is True
 
         # create a new file and call insertFilesInDir again
         test_file3 = open(path + "/test3.dat", "w")
@@ -626,15 +623,14 @@ def test_insert_files_in_dir():
             raise_exception_on_error=False,
             flags={
                 "InsertFilesInDir": path_on_server})
-        assert_is_not_none(e.messages["Info", 0])
-        assert_equal(e.messages["Info", 0][0],
-                     "Files count in testfolder/: 3")
+        assert e.messages["Info", 0] is not None
+        assert e.messages["Info", 0][0] == "Files count in testfolder/: 3"
 
         # only the new file is given back...
-        assert_equal(1, len(e))
-        assert_false(e[0].is_valid())
-        assert_equal(e[0].name, "test3.dat")
-        assert_equal(e[0].path, "/testfolder/test3.dat")
+        assert 1 == len(e)
+        assert e[0].is_valid() is False
+        assert e[0].name == "test3.dat"
+        assert e[0].path == "/testfolder/test3.dat"
 
         f = models.Container()
         f.insert(
@@ -642,14 +638,13 @@ def test_insert_files_in_dir():
             raise_exception_on_error=False,
             flags={
                 "InsertFilesInDir": path_on_server})
-        assert_is_not_none(f.messages["Info", 0])
-        assert_equal(f.messages["Info", 0][0],
-                     "Files count in testfolder/: 3")
+        assert f.messages["Info", 0] is not None
+        assert f.messages["Info", 0][0] == "Files count in testfolder/: 3"
         # only the new file is given back...
-        assert_equal(1, len(f))
-        assert_true(f[0].is_valid())
-        assert_equal(f[0].name, "test3.dat")
-        assert_equal(f[0].path, "/testfolder/test3.dat")
+        assert 1 == len(f)
+        assert f[0].is_valid() is True
+        assert f[0].name == "test3.dat"
+        assert f[0].path == "/testfolder/test3.dat"
 
     finally:
         try: