From cfdc90f8a7df04afd589cd4a8fca0e81ab3fa473 Mon Sep 17 00:00:00 2001
From: James McKinney <26463+jpmckinney@users.noreply.github.com>
Date: Wed, 4 Oct 2023 01:30:37 -0400
Subject: [PATCH] fix: Fix TableSet.print_structure for nested tablesets, #765

---
 CHANGELOG.rst                     |  1 +
 agate/tableset/print_structure.py | 16 +++++++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 03109549..1afef6ad 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -3,6 +3,7 @@ Unreleased
 
 * feat: Lowercase the ``null_values`` provided to individual data types, since all comparisons to ``null_values`` are case-insensitive. (#770)
 * feat: :class:`.Mean` works with :class:`.TimeDelta`. (#761)
+* fix: Fix :meth:`.TableSet.print_structure` for nested tablesets. (#765)
 
 1.7.1 - Jan 4, 2023
 -------------------
diff --git a/agate/tableset/print_structure.py b/agate/tableset/print_structure.py
index e8422494..0ceb9295 100644
--- a/agate/tableset/print_structure.py
+++ b/agate/tableset/print_structure.py
@@ -2,6 +2,15 @@
 
 from agate.data_types import Text
 from agate.table import Table
+from agate.tableset import TableSet
+
+
+def _items(key, value):
+    if isinstance(value, TableSet):
+        for k, v in value.items():
+            yield from _items(key + (k,), v)
+    else:
+        yield key, value
 
 
 def print_structure(self, max_rows=20, output=sys.stdout):
@@ -16,10 +25,11 @@ def print_structure(self, max_rows=20, output=sys.stdout):
     :returns:
         None
     """
-    max_length = min(len(self.items()), max_rows)
+    items = list(_items((), self))
+    max_length = min(len(items), max_rows)
 
-    name_column = self.keys()[0:max_length]
-    type_column = [str(len(table.rows)) for key, table in self.items()[0:max_length]]
+    name_column = ['.'.join(key) for key, value in items][0:max_length]
+    type_column = [str(len(table.rows)) for key, table in items[0:max_length]]
     rows = zip(name_column, type_column)
     column_names = ['table', 'rows']
     text = Text()