Make tables look less awful

pedal/core/formatting.py

@@ -2,7 +2,8 @@
 Utilities and classes related to formatting a Feedback Message.
 """
 from pedal.core.location import Location
-from pedal.utilities.text import inject_line
+from pedal.utilities.text import inject_line, render_table
+
 
 def chomp_spec(format_spec, word):
     """ Return a new version of format_spec without the ``word`` and
@@ -126,10 +127,7 @@ def exception(self, exception):
         return self.pre(exception)
 
     def table(self, rows, columns):
-        result = [" | ".join(columns)]
-        for row in rows:
-            result.append(" | ".join(row))
-        return "\n" + ("\n".join(result))
+        return "\n" + render_table(rows, columns, " | ")
 
     def check_mark(self):
         # TODO: should be ✓, right?

pedal/environments/terminal.py

@@ -13,6 +13,11 @@
 from pedal.resolvers.simple import resolve
 from pedal.core.formatting import Formatter
 
+try:
+    import tabulate
+except ImportError:
+    tabulate = None
+
 RESET = "\033[0;0m"
 REVERSE = "\033[;7m"
 UNDERLINE = "\033[4m"
@@ -42,6 +47,12 @@ def filename(self, filename):
             filename = os.path.basename(filename)
         return f"{UNDERLINE}{filename}{RESET}"
 
+    def table(self, rows, columns):
+        if tabulate:
+            return self.pre(tabulate.tabulate(rows, headers=columns, tablefmt="plain"))
+        else:
+            return super().table(rows, columns)
+
 
 @make_resolver
 def resolve_on_terminal(report=MAIN_REPORT):

pedal/utilities/text.py

@@ -84,3 +84,35 @@ def inject_line(code, line_number, new_line):
     lines = code.split("\n")
     lines.insert(line_number, new_line)
     return "\n".join(lines)
+
+
+def render_table(rows, headers=None, separator=" | ", max_width=120):
+    """
+    Simple function to render table with fixed width.
+
+    TODO: Try to resize table to make it fit comfortably within 120 characters,
+        e.g., by removing separators, or by wrapping text.
+
+    Based on: https://stackoverflow.com/a/52247284/1718155
+    """
+    table = [headers] + rows if headers else rows
+    longest_cols = [
+        (max([len(str(row[i])) for row in table]))
+        for i in range(len(table[0]))
+    ]
+    total_width = sum(longest_cols) + (len(longest_cols)-1) * len(separator)
+    if max_width is not None:
+        if total_width > max_width:
+            # Maybe we can trim the separator?
+            if separator:
+                shorter_separator = separator.strip()
+                # Oops, we already tried stripping. What about removing it?
+                if shorter_separator == separator:
+                    shorter_separator = ""
+                return render_table(rows, headers, shorter_separator, max_width)
+    row_format = separator.join(["{:>" + str(longest_col) + "}"
+                                for longest_col in longest_cols])
+    result = [row_format.format(*row) for row in table]
+    if headers:
+        result.insert(1, "="*total_width)
+    return "\n".join(result)

tests/test_assertion_functions.py

@@ -78,12 +78,13 @@ def test_unit_test_partial_credit_true(self):
 You passed 3/5 tests.
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     1, 2 | 2 | 3
-  |     0, 0 | 0 | 0
-  |     0, 3 | 3 | 3
-  |     0, 5 | 5 | 5
-× |     1, 3 | 3 | 4""")
+  | Arguments | Returned | Expected
+===================================
+× |      1, 2 |        2 |        3
+  |      0, 0 |        0 |        0
+  |      0, 3 |        3 |        3
+  |      0, 5 |        5 |        5
+× |      1, 3 |        3 |        4""")
 
     def test_bad_name_error_concatenation(self):
         with Execution("""
@@ -125,9 +126,10 @@ def add(a, b):
 You passed 1/2 tests.
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     1, 2 | -1 | 3
-  |     0, 0 | 0 | 0""")
+  | Arguments | Returned | Expected
+===================================
+× |      1, 2 |       -1 |        3
+  |      0, 0 |        0 |        0""")
 
     def test_unit_test_blocked_function(self):
         with Execution("""
@@ -142,8 +144,9 @@ def summate(numbers: [int]) -> int:
 You passed 0/1 tests.
 
 I ran your function summate on some new arguments.
- | Arguments | Returned | Expected
-× |     [1, 2, 3] | You are not allowed to call 'sum'. | 6""")
+  |     Arguments |                           Returned | Expected
+=================================================================
+× |     [1, 2, 3] | You are not allowed to call 'sum'. |        6""")
 
     def test_unit_test_extra_context(self):
         with Execution('def add(a, b): return b', run_tifa=False) as e:
@@ -163,9 +166,10 @@ def test_unit_test_extra_context(self):
     data = [5, 3, 4]
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     data, 5 | 5 | 17
-× |     [3, 3], 3 | 3 | 9""")
+  |     Arguments | Returned | Expected
+=======================================
+× |       data, 5 |        5 |       17
+× |     [3, 3], 3 |        3 |        9""")
 
     def test_unit_test_extra_context_run(self):
         with Execution('def add(a, b): return b', run_tifa=False) as e:
@@ -187,9 +191,10 @@ def test_unit_test_extra_context_run(self):
     data2 = [1,2,3]
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     data, 5 | 5 | 17
-× |     [3, 3], 3 | 3 | 9""")
+  |     Arguments | Returned | Expected
+=======================================
+× |       data, 5 |        5 |       17
+× |     [3, 3], 3 |        3 |        9""")
 
     def test_unit_test_extra_context_calls(self):
         with Execution('def add(a, b): return b', run_tifa=False) as e:
@@ -214,10 +219,11 @@ def test_unit_test_extra_context_calls(self):
     data2 = [1,2,3]
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     data, 5 | 5 | 17
-× |     data2, 5 | 5 | 17
-× |     [3, 3], 3 | 3 | 9""")
+  |     Arguments | Returned | Expected
+=======================================
+× |       data, 5 |        5 |       17
+× |      data2, 5 |        5 |       17
+× |     [3, 3], 3 |        3 |        9""")
 
 if __name__ == '__main__':
     unittest.main(buffer=False)

tests/test_assertions_runtime.py

@@ -256,10 +256,11 @@ def test_assert_group_fails_some_errors(self):
 You passed 1/3 tests.
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-  |     1, 2 | 3 | 3
-× |     1, 4 | 5 | 6
-× |     1, '2' | unsupported operand type(s) for +: 'int' and 'str' | 3""")
+  |  Arguments |                                           Returned | Expected
+==============================================================================
+  |       1, 2 |                                                  3 |        3
+× |       1, 4 |                                                  5 |        6
+× |     1, '2' | unsupported operand type(s) for +: 'int' and 'str' |        3""")
 
     def test_assert_group_fails_all(self):
         with Execution('def add(a, b): return a+b', run_tifa=False) as e:
@@ -272,10 +273,11 @@ def test_assert_group_fails_all(self):
 You passed 0/3 tests.
 
 I ran your function add on some new arguments.
- | Arguments | Returned | Expected
-× |     1, 3 | 4 | 3
-× |     1, 4 | 5 | 6
-× |     1, 3 | 4 | 3""")
+  | Arguments | Returned | Expected
+===================================
+× |      1, 3 |        4 |        3
+× |      1, 4 |        5 |        6
+× |      1, 3 |        4 |        3""")
 
     def test_assert_group_passes(self):
         with Execution('def add(a, b): return a+b', run_tifa=False) as e: