Improve NetworkX module import (#21)

* Improve NetworkX module import
* Add Networkx dependencies to Dockerfiles

query_modules/graph_analyzer.py

@@ -1,11 +1,21 @@
+import sys
 import mgp
-
 from collections import OrderedDict
 from itertools import chain, repeat
 from inspect import cleandoc
-from typing import List, Tuple, Optional
+from typing import List, Tuple
-from mgp_networkx import MemgraphMultiDiGraph
+try:
-import networkx as nx
+    import networkx as nx
+except ImportError as import_error:
+    sys.stderr.write((
+        '\n'
+        'NOTE: Please install networkx to be able to use graph_analyzer '
+        'module. Using Python:\n'
+        + sys.version +
+        '\n'))
+    raise import_error
+# Imported last because it also depends on networkx.
+from mgp_networkx import MemgraphMultiDiGraph  # noqa E402
 
 
 _MAX_LIST_SIZE = 10

query_modules/mgp_networkx.py

@@ -1,7 +1,16 @@
+import sys
 import mgp
-
 import collections
-import networkx as nx
+try:
+    import networkx as nx
+except ImportError as import_error:
+    sys.stderr.write((
+        '\n'
+        'NOTE: Please install networkx to be able to use Memgraph NetworkX '
+        'wrappers. Using Python:\n'
+        + sys.version +
+        '\n'))
+    raise import_error
 
 
 class MemgraphAdjlistOuterDict(collections.abc.Mapping):

query_modules/nxalg.py

@@ -1,8 +1,22 @@
+import sys
 import mgp
-from mgp_networkx import (MemgraphMultiDiGraph, MemgraphDiGraph,
+try:
+    import networkx as nx
+    import numpy  # noqa E401
+    import scipy  # noqa E401
+except ImportError as import_error:
+    sys.stderr.write((
+        '\n'
+        'NOTE: Please install networkx, numpy, scipy to be able to '
+        'use proxied NetworkX algorithms. E.g., CALL nxalg.pagerank(...).\n'
+        'Using Python:\n'
+        + sys.version +
+        '\n'))
+    raise import_error
+# Imported last because it also depends on networkx.
+from mgp_networkx import (MemgraphMultiDiGraph, MemgraphDiGraph,  # noqa: E402
                           MemgraphMultiGraph, MemgraphGraph,
                           PropertiesDictionary)
-import networkx as nx
 
 
 # networkx.algorithms.approximation.connectivity.node_connectivity

query_modules/wcc.py

@@ -1,6 +1,15 @@
+import sys
 import mgp
-
+try:
-import networkx as nx
+    import networkx as nx
+except ImportError as import_error:
+    sys.stderr.write(
+        '\n'
+        'NOTE: Please install networkx to be able to use wcc module.\n'
+        'Using Python:\n'
+        + sys.version +
+        '\n')
+    raise import_error
 
 
 @mgp.read_proc
@@ -28,8 +37,10 @@ def get_components(vertices: mgp.List[mgp.Vertex],
     vertices labeled `Person` and edges between such vertices can be obtained
     using the following openCypher query:
 
-    MATCH (n:Person)-[e]->(m:Person) WITH collect(n) AS nodes, collect(e) AS edges
+    MATCH (n:Person)-[e]->(m:Person)
-    CALL wcc.get_components(nodes, edges) YIELD * RETURN n_components, components;
+    WITH collect(n) AS nodes, collect(e) AS edges
+    CALL wcc.get_components(nodes, edges) YIELD *
+    RETURN n_components, components;
     '''
     g = nx.DiGraph()
     g.add_nodes_from(vertices)

release/docker/memgraph_community.dockerfile

@@ -7,7 +7,7 @@ RUN apt-get update && apt-get install -y \
     --no-install-recommends \
   && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
-RUN pip3 install networkx
+RUN pip3 install networkx==2.4 numpy==1.19.2 scipy==1.5.2
 
 COPY ${deb_release} /
 

release/docker/memgraph_enterprise.dockerfile

@@ -7,7 +7,7 @@ RUN apt-get update && apt-get install -y \
     --no-install-recommends \
   && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
-RUN pip3 install networkx
+RUN pip3 install networkx==2.4 numpy==1.19.2 scipy==1.5.2
 
 COPY ${deb_release} /