René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Coloring by boolean column type does not work","articleBody":"When trying to color a scatter plot by a `bool` column datatype, the colors do not show:\r\n\r\n(see attached file for data)\r\n\r\n```\r\ngrouped.dtypes\r\n\r\nmean_ape            float64\r\nmeasurement_type     object\r\nnote                 object\r\nparameters           object\r\nn_estimators          int64\r\nmax_depth             int64\r\nbootstrap              bool\r\nmax_features        float64\r\n\r\nfig = px.scatter(\r\n    grouped,\r\n    x=\"n_estimators\",\r\n    y=\"mean_ape\",\r\n    facet_row=\"measurement_type\",\r\n    color=\"bootstrap\",\r\n    title=\"Error vs Number of Estimators Colored by Bootstrap\",\r\n    height=1000, width=1600\r\n)\r\n```\r\n\u003cimg width=\"1433\" alt=\"Screen Shot 2019-06-17 at 08 52 13 EDT\" src=\"https://user-images.githubusercontent.com/17484616/59605663-45849600-90dd-11e9-898b-155736577bb6.png\"\u003e\r\n\r\nHowever, if I convert the `bool` column to a `str`, then the colors correctly appear:\r\n\r\n```\r\nnew_grouped = grouped.copy()\r\nnew_grouped['bootstrap'] = new_grouped['bootstrap'].astype(str)\r\n\r\nfig = px.scatter(\r\n    new_grouped,\r\n    x=\"n_estimators\",\r\n    y=\"mean_ape\",\r\n    facet_row=\"measurement_type\",\r\n    color=\"bootstrap\",\r\n    title=\"Error vs Number of Estimators Colored by Bootstrap\",\r\n    height=1000, width=1600\r\n)\r\n```\r\n\r\n\u003cimg width=\"1441\" alt=\"Screen Shot 2019-06-17 at 08 53 13 EDT\" src=\"https://user-images.githubusercontent.com/17484616/59605745-6e0c9000-90dd-11e9-95d4-9ecd24e20b24.png\"\u003e\r\n\r\n[grouped.csv.zip](https://github.com/plotly/plotly_express/files/3297037/grouped.csv.zip)\r\n\r\n","author":{"url":"https://github.com/WillKoehrsen","@type":"Person","name":"WillKoehrsen"},"datePublished":"2019-06-17T12:56:05.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/2121/plotly.py/issues/2121"}