Solve ImportError in Python < 3.5 due to cyclic import

README.md

@@ -59,6 +59,9 @@ This list is especially useful for the `libbmc.papers.identifiers` module,
 which is using it to loop through all the available identifier types, to fetch
 for them in the paper and retrieve BibTeX from it.
 
+You can also write a specific citation extraction module for this repository
+in `libbmc/citations/repositories/{REPOSITORY}.py`.
+
 
 ## License
 

libbmc/citations/bbl.py

@@ -1,5 +1,5 @@
 """
-This files contains all the functions to extract DOIs of citations from .bbl
+This file contains all the functions to extract DOIs of citations from .bbl
 files.
 """
 import os

libbmc/citations/bibtex.py

@@ -1,5 +1,5 @@
 """
-This files contains all the functions to extract DOIs of citations from
+This file contains all the functions to extract DOIs of citations from
 BibTeX files.
 """
 import os

libbmc/citations/pdf.py

@@ -1,5 +1,5 @@
 """
-This files contains all the functions to extract DOIs of citations from
+This file contains all the functions to extract DOIs of citations from
 PDF files.
 """
 import os

libbmc/citations/plaintext.py

@@ -1,5 +1,5 @@
 """
-This files contains all the functions to extract DOIs of citations from
+This file contains all the functions to extract DOIs of citations from
 plaintext files.
 """
 import os

libbmc/citations/repositories/arxiv.py

@@ -0,0 +1,50 @@
+"""
+This file contains all the functions to extract DOIs of citations from arXiv
+papers.
+"""
+from libbmc.citations import bbl
+from libbmc.repositories import arxiv
+
+
+def get_plaintext_citations(arxiv_id):
+    """
+    Get the citations of a given preprint, in plain text.
+
+    .. note::
+
+        Bulk download of sources from arXiv is not permitted by their API. \
+                You should have a look at http://arxiv.org/help/bulk_data_s3.
+
+    :param arxiv_id: The arXiv id (e.g. ``1401.2910`` or ``1401.2910v1``) in \
+            a canonical form.
+    :returns:  A list of cleaned plaintext citations.
+    """
+    plaintext_citations = []
+    # Get the list of bbl files for this preprint
+    bbl_files = arxiv.get_bbl(arxiv_id)
+    for bbl_file in bbl_files:
+        # Fetch the cited DOIs for each of the bbl files
+        plaintext_citations.extend(bbl.get_plaintext_citations(bbl_file))
+    return plaintext_citations
+
+
+def get_cited_dois(arxiv_id):
+    """
+    Get the DOIs of the papers cited in a .bbl file.
+
+    .. note::
+
+        Bulk download of sources from arXiv is not permitted by their API. \
+                You should have a look at http://arxiv.org/help/bulk_data_s3.
+
+    :param arxiv_id: The arXiv id (e.g. ``1401.2910`` or ``1401.2910v1``) in \
+            a canonical form.
+    :returns: A dict of cleaned plaintext citations and their associated DOI.
+    """
+    dois = {}
+    # Get the list of bbl files for this preprint
+    bbl_files = arxiv.get_bbl(arxiv_id)
+    for bbl_file in bbl_files:
+        # Fetch the cited DOIs for each of the bbl files
+        dois.update(bbl.get_cited_dois(bbl_file))
+    return dois

libbmc/repositories/arxiv.py

@@ -18,7 +18,6 @@ from requests.exceptions import RequestException
 
 from libbmc import __valid_identifiers__
 from libbmc import tools
-from libbmc.citations import bbl
 
 # Append arXiv to the valid identifiers list
 __valid_identifiers__ += ["repositories.arxiv"]
@@ -475,25 +474,3 @@ def get_bbl(arxiv_id):
     bbl_files = [tar_file.extractfile(member).read().decode(tarfile.ENCODING)
                  for member in bbl_files]
     return bbl_files
-
-
-def get_citations(arxiv_id):
-    """
-    Get the DOIs cited by a given preprint.
-
-    .. note::
-
-        Bulk download of sources from arXiv is not permitted by their API. \
-                You should have a look at http://arxiv.org/help/bulk_data_s3.
-
-    :param arxiv_id: The arXiv id (e.g. ``1401.2910`` or ``1401.2910v1``) in \
-            a canonical form.
-    :returns: A dict of cleaned plaintext citations and their associated DOI.
-    """
-    dois = {}
-    # Get the list of bbl files for this preprint
-    bbl_files = get_bbl(arxiv_id)
-    for bbl_file in bbl_files:
-        # Fetch the cited DOIs for each of the bbl files
-        dois.update(bbl.get_cited_dois(bbl_file))
-    return dois