From c491fe8829c939bb20aeaf5661b645ea98089217 Mon Sep 17 00:00:00 2001
From: Allen Downey <downey@allendowney.com>
Date: Fri, 13 Nov 2020 11:13:07 -0500
Subject: [PATCH] Updating

---
 01_query.ipynb | 85 +++++++++++++++++++++++++++++++++++++++++---------
 05_join.ipynb  |  2 +-
 2 files changed, 71 insertions(+), 16 deletions(-)

diff --git a/01_query.ipynb b/01_query.ipynb
index fb70e3e..8c99949 100644
--- a/01_query.ipynb
+++ b/01_query.ipynb
@@ -141,7 +141,11 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [],
    "source": [
     "# If we're running on Colab, install libraries\n",
@@ -194,9 +198,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**Optional detail**\n",
-    "\n",
-    "> Running this import statement has the effect of creating a [TAP+](http://www.ivoa.net/documents/TAP/) connection; TAP stands for \"Table Access Protocol\".  It is a network protocol for sending queries to the database and getting back the results.  We're not sure why it seems to create two connections."
+    "Running this import statement has the effect of creating a [TAP+](http://www.ivoa.net/documents/TAP/) connection; TAP stands for \"Table Access Protocol\".  It is a network protocol for sending queries to the database and getting back the results.  We're not sure why it seems to create two connections."
    ]
   },
   {
@@ -236,7 +238,11 @@
   {
    "cell_type": "code",
    "execution_count": 4,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-output"
+    ]
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -362,7 +368,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 7,
    "metadata": {},
    "outputs": [
     {
@@ -377,10 +383,10 @@
     {
      "data": {
       "text/plain": [
-       "<astroquery.utils.tap.model.taptable.TapTableMeta at 0x7f922376e0a0>"
+       "<astroquery.utils.tap.model.taptable.TapTableMeta at 0x7fb565288520>"
       ]
      },
-     "execution_count": 5,
+     "execution_count": 7,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -437,6 +443,27 @@
     "What happens?  Is the error message helpful?  If you had not made this error deliberately, would you have been able to figure it out?"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Solution\n",
+    "\n",
+    "# The error message, last time we tried, was\n",
+    "\n",
+    "# Retrieving table 'gaiadr2.gaiadr2.gaia_source'\n",
+    "# 500 Error 500:\n",
+    "# esavo.tap.TAPException: esavo.tap.TAPException: Schema cannot be null\n",
+    "\n",
+    "# Which is not remotely helpful.\n",
+    "\n",
+    "# The point of this exercise is to alert the participants to the difficulty\n",
+    "# of debugging queries with VERY limited feedback.  So developing and testing\n",
+    "# incrementally is very important."
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -449,7 +476,11 @@
   {
    "cell_type": "code",
    "execution_count": 7,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-output"
+    ]
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -581,7 +612,11 @@
   {
    "cell_type": "code",
    "execution_count": 8,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "remove-cell"
+    ]
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -670,7 +705,11 @@
   {
    "cell_type": "code",
    "execution_count": 9,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -1166,7 +1205,11 @@
   {
    "cell_type": "code",
    "execution_count": 18,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [],
    "source": [
     "# Solution\n",
@@ -1184,7 +1227,11 @@
   {
    "cell_type": "code",
    "execution_count": 19,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [],
    "source": [
     "# Solution\n",
@@ -1507,7 +1554,11 @@
   {
    "cell_type": "code",
    "execution_count": 29,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [],
    "source": [
     "# Solution\n",
@@ -1523,7 +1574,11 @@
   {
    "cell_type": "code",
    "execution_count": 30,
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide-cell"
+    ]
+   },
    "outputs": [
     {
      "name": "stdout",
diff --git a/05_join.ipynb b/05_join.ipynb
index 1484d3d..e4d80bf 100644
--- a/05_join.ipynb
+++ b/05_join.ipynb
@@ -167,7 +167,7 @@
     "\n",
     "Selecting stars with `bp-rp` less than 2 excludes many class M dwarf stars, which are low temperature, low luminosity.  A star like that at GD-1's distance would be hard to detect, so if it is detected, it it more likely to be in the foreground.\n",
     "\n",
-    "Now, to select stars with the age and metal richness we expect in GD-1, we will use `g − i` color and apparent `g`-band magnitude, which are available from the Pan-STARRS survey."
+    "Now, to select stars with the age and metal richness we expect in GD-1, we will use `g - i` color and apparent `g`-band magnitude, which are available from the Pan-STARRS survey."
    ]
   },
   {