Fix build error caused by circular dependencies

isatools/convert/isatab2sra.py

@@ -4,7 +4,6 @@
 from zipfile import ZipFile
 import logging
 from isatools import isatab
-from isatools.convert import isatab2json, json2sra
 import json
 from io import StringIO
 
@@ -105,6 +104,7 @@ def create_sra(source_path, dest_path, config_path=default_config_dir):
 
 
 def convert(source_path, dest_path, validate_first=True):
+    from isatools.convert import isatab2json, json2sra
     isa_json = isatab2json.convert(source_path, validate_first=validate_first)
     isa_json_fp = StringIO(json.dumps(isa_json))
     isa_json_fp.name = "BII-S-3.json"

isatools/convert/json2sra.py

@@ -1,5 +1,5 @@
 from isatools import isajson, sra
-from isatools.convert import json2isatab, isatab2sra
+
 from glob import glob
 import os
 import logging
@@ -14,6 +14,7 @@ def convert(json_fp, path, config_dir=None):
     :param path: Directory for output to be written
     :param config_dir: path to JSON configuration
     """
+    from isatools.convert import json2isatab, isatab2sra
     json2isatab.convert(json_fp=json_fp, path=path, config_dir=config_dir)
     isatab2sra.create_sra(path, path)
     for f in glob(path + '/*.txt'):  # remove generated isatab files