Make terminaltables truly optional (#71)

sample_sheet/__init__.py

@@ -14,7 +14,6 @@
 from requests.structures import CaseInsensitiveDict
 from smart_open import smart_open  # type: ignore
 from tabulate import tabulate  # type: ignore
-from terminaltables import SingleTable  # type: ignore
 from typing import (
     Any,
     Generator,
@@ -33,6 +32,15 @@
 
 __version__ = '0.8.0'
 
+
+try:  # pragma: no cover
+    from terminaltables import SingleTable  # type: ignore
+
+    HAS_TERMINALTABLES = True
+except ImportError:
+    HAS_TERMINALTABLES = False
+
+
 DESIGN_HEADER: List[str] = [
     'Sample_ID',
     'Sample_Name',
@@ -929,11 +937,14 @@ def __str__(self) -> str:
 
         """
         try:
-            isatty = os.isatty(sys.stdout.fileno())
+            in_terminal = os.isatty(sys.stdout.fileno())
         except OSError:  # pragma: no cover
-            isatty = False
+            in_terminal = False
 
-        return self._repr_tty_() if isatty else self.__repr__()
+        if in_terminal and HAS_TERMINALTABLES:
+            return self._repr_tty_()
+        else:
+            return self.__repr__()
 
     def _repr_tty_(self) -> str:
         """Return a summary of this sample sheet in a TTY compatible codec."""

setup.py

@@ -16,13 +16,8 @@
     license='MIT',
     zip_safe=True,
     packages=find_packages(),
-    install_requires=[
-        'click',
-        'smart_open>=1.5.4',
-        'tabulate',
-        'terminaltables',
-    ],
-    # extras_requires={'cli': ['terminaltables']},
+    install_requires=['click', 'smart_open>=1.5.4', 'tabulate'],
+    extras_requires={'cli': ['terminaltables']},
     scripts=['scripts/sample-sheet'],
     keywords='illumina samplesheet sample sheet parser bioinformatics',
     classifiers=[

tests/test_sample_sheet.py

@@ -18,6 +18,7 @@
 from requests.exceptions import HTTPError
 
 from sample_sheet import *  # Test import of __all__
+from sample_sheet import HAS_TERMINALTABLES
 
 RESOURCES = Path(__file__).absolute().resolve().parent / 'resources'
 
@@ -717,6 +718,11 @@ def test_repr(self):
             'SampleSheet(\'{}\')'.format(infile),
         )
 
+    @pytest.mark.xfail(reasion="Not sure if multi-line diff is correct")
+    @pytest.mark.skipif(
+        not HAS_TERMINALTABLES,
+        reason="We need `terminaltables` installed here",
+    )
     def test_repr_tty(self):
         """Test ``_repr_tty_()``"""
         self.maxDiff = 3000
@@ -763,4 +769,4 @@ def test_repr_tty(self):
             '\n└───────────┴──────────────────┘'
         )
 
-        # self.assertMultiLineEqual(source, target)
+        self.assertMultiLineEqual(source, target)