fix: Use uproot3 namespace (#1192)

* Use uproot3 library namespace explicitly to avoid errors from uproot-methods v0.9.1
   - Use uproot3 in 'xmlio' extra
* Use pattern: import uproot3 as uproot

Author: matthewfeickert

setup.py

@@ -8,7 +8,7 @@
     ],
     'torch': ['torch~=1.2'],
     'jax': ['jax~=0.2.4', 'jaxlib~=0.1.56'],
-    'xmlio': ['uproot~=3.6'],  # Future proof against uproot4 API changes
+    'xmlio': ['uproot3~=3.14'],  # Future proof against uproot4 API changes
     'minuit': ['iminuit~=1.4.3'],  # v1.5.0 breaks pyhf for 32b TensorFlow and PyTorch
 }
 extras_require['backends'] = sorted(
@@ -40,7 +40,6 @@
             'papermill~=2.0',
             'nteract-scrapbook~=0.2',
             'jupyter',
-            'uproot~=3.3',
             'graphviz',
             'jsonpatch',
         ]

src/pyhf/cli/rootio.py

@@ -32,7 +32,7 @@ def cli():
 def xml2json(entrypoint_xml, basedir, output_file, track_progress):
     """Entrypoint XML: The top-level XML file for the PDF definition."""
     try:
-        import uproot
+        import uproot3 as uproot
 
         assert uproot
     except ImportError:
@@ -61,7 +61,7 @@ def xml2json(entrypoint_xml, basedir, output_file, track_progress):
 def json2xml(workspace, output_dir, specroot, dataroot, resultprefix, patch):
     """Convert pyhf JSON back to XML + ROOT files."""
     try:
-        import uproot
+        import uproot3 as uproot
 
         assert uproot
     except ImportError:

src/pyhf/readxml.py

@@ -6,7 +6,7 @@
 import xml.etree.ElementTree as ET
 import numpy as np
 import tqdm
-import uproot
+import uproot3 as uproot
 import re
 
 log = logging.getLogger(__name__)

src/pyhf/writexml.py

@@ -5,7 +5,7 @@
 import pkg_resources
 import xml.etree.cElementTree as ET
 import numpy as np
-import uproot
+import uproot3 as uproot
 from uproot_methods.classes import TH1
 
 from .mixins import _ChannelSummaryMixin

tests/test_import.py

@@ -1,7 +1,7 @@
 import pyhf
 import pyhf.readxml
 import numpy as np
-import uproot
+import uproot3 as uproot
 from pathlib import Path
 import pytest
 import xml.etree.cElementTree as ET