Fixes to gr.Examples (#1952)

* still working

* remove exampleset logic

* wip

* added tests and fix

* fixed header issue

* more tests

* formatting

* removed print

* Update gradio/examples.py

* used context managers

* more readable

* removed unnecessary start index

* formatting

gradio/components.py

@@ -4293,7 +4293,12 @@ class Dataset(Clickable, Component):
         Component.__init__(self, visible=visible, elem_id=elem_id, **kwargs)
         self.components = [get_component_instance(c, render=False) for c in components]
         self.type = type
-        self.headers = headers or [c.label for c in self.components]
+        if headers is not None:
+            self.headers = headers
+        elif all([c.label is None for c in self.components]):
+            self.headers = []
+        else:
+            self.headers = [c.label or "" for c in self.components]
         self.samples = samples
 
     def get_config(self):

gradio/examples.py

@@ -6,10 +6,12 @@ from __future__ import annotations
 import csv
 import os
 import shutil
+from pathlib import Path
 from typing import TYPE_CHECKING, Any, Callable, List, Optional, Tuple
 
 from gradio import utils
 from gradio.components import Dataset
+from gradio.context import Context
 from gradio.documentation import document, set_documentation_group
 from gradio.flagging import CSVLogger
 
@@ -18,6 +20,7 @@ if TYPE_CHECKING:  # Only import for type checking (to avoid circular imports).
     from gradio.components import Component
 
 CACHED_FOLDER = "gradio_cached_examples"
+LOG_FILE = "log.csv"
 
 set_documentation_group("component-helpers")
 
@@ -45,7 +48,7 @@ class Examples:
     ):
         """
         Parameters:
-            examples: example inputs that can be clicked to populate specific components. Should be nested list, in which the outer list consists of samples and each inner list consists of an input corresponding to each input component. A string path to a directory of examples can also be provided.
+            examples: example inputs that can be clicked to populate specific components. Should be nested list, in which the outer list consists of samples and each inner list consists of an input corresponding to each input component. A string path to a directory of examples can also be provided. If there are multiple input components and a directory is provided, a log.csv file must be present in the directory to link corresponding inputs.
             inputs: the component or list of components corresponding to the examples
             outputs: optionally, provide the component or list of components corresponding to the output of the examples. Required if `cache` is True.
             fn: optionally, provide the function to run to generate the outputs corresponding to the examples. Required if `cache` is True.
@@ -60,6 +63,8 @@ class Examples:
         if not isinstance(outputs, list):
             outputs = [outputs]
 
+        working_directory = Path().absolute()
+
         if examples is None:
             raise ValueError("The parameter `examples` cannot be None")
         elif isinstance(examples, list) and (
@@ -75,34 +80,22 @@ class Examples:
                 raise FileNotFoundError(
                     "Could not find examples directory: " + examples
                 )
-            log_file = os.path.join(examples, "log.csv")
-            if not os.path.exists(log_file):
+            working_directory = examples
+            if not os.path.exists(os.path.join(examples, LOG_FILE)):
                 if len(inputs) == 1:
-                    exampleset = [
-                        [os.path.join(examples, item)] for item in os.listdir(examples)
-                    ]
+                    examples = [[e] for e in os.listdir(examples)]
                 else:
                     raise FileNotFoundError(
                         "Could not find log file (required for multiple inputs): "
-                        + log_file
+                        + LOG_FILE
                     )
             else:
-                with open(log_file) as logs:
-                    exampleset = list(csv.reader(logs))
-                    exampleset = exampleset[1:]  # remove header
-            for i, example in enumerate(exampleset):
-                for j, (component, cell) in enumerate(
-                    zip(
-                        inputs + outputs,
-                        example,
-                    )
-                ):
-                    exampleset[i][j] = component.restore_flagged(
-                        examples,
-                        cell,
-                        None,
-                    )
-            examples = exampleset
+                with open(os.path.join(examples, LOG_FILE)) as logs:
+                    examples = list(csv.reader(logs))
+                    examples = [
+                        examples[i][: len(inputs)] for i in range(1, len(examples))
+                    ]  # remove header and unnecessary columns
+
         else:
             raise ValueError(
                 "The parameter `examples` must either be a directory or a nested "
@@ -135,21 +128,22 @@ class Examples:
         self.cache_examples = cache_examples
         self.examples_per_page = examples_per_page
 
-        dataset = Dataset(
+        with utils.set_directory(working_directory):
+            self.processed_examples = [
+                [
+                    component.preprocess_example(sample)
+                    for component, sample in zip(inputs_with_examples, example)
+                ]
+                for example in non_none_examples
+            ]
+
+        self.dataset = Dataset(
             components=inputs_with_examples,
             samples=non_none_examples,
             type="index",
         )
 
-        self.processed_examples = [
-            [
-                component.preprocess_example(sample)
-                for component, sample in zip(inputs_with_examples, example)
-            ]
-            for example in non_none_examples
-        ]
-
-        self.cached_folder = os.path.join(CACHED_FOLDER, str(dataset._id))
+        self.cached_folder = os.path.join(CACHED_FOLDER, str(self.dataset._id))
         self.cached_file = os.path.join(self.cached_folder, "log.csv")
         if cache_examples:
             self.cache_interface_examples()
@@ -163,13 +157,14 @@ class Examples:
                 processed_example = self.processed_examples[example_id]
             return utils.resolve_singleton(processed_example)
 
-        dataset.click(
-            load_example,
-            inputs=[dataset],
-            outputs=inputs_with_examples + (outputs if cache_examples else []),
-            _postprocess=False,
-            queue=False,
-        )
+        if Context.root_block:
+            self.dataset.click(
+                load_example,
+                inputs=[self.dataset],
+                outputs=inputs_with_examples + (outputs if cache_examples else []),
+                _postprocess=False,
+                queue=False,
+            )
 
     def cache_interface_examples(self) -> None:
         """Caches all of the examples from an interface."""

gradio/utils.py

@@ -11,9 +11,11 @@ import os
 import pkgutil
 import random
 import warnings
+from contextlib import contextmanager
 from copy import deepcopy
 from distutils.version import StrictVersion
 from enum import Enum
+from pathlib import Path
 from typing import TYPE_CHECKING, Any, Callable, Dict, Generator, NewType, Tuple, Type
 
 import aiohttp
@@ -585,3 +587,14 @@ class Request:
     @property
     def status(self):
         return self._status
+
+
+@contextmanager
+def set_directory(path: Path):
+    """Context manager that sets the working directory to the given path."""
+    origin = Path().absolute()
+    try:
+        os.chdir(path)
+        yield
+    finally:
+        os.chdir(origin)

test/test_examples.py

@@ -1,19 +1,71 @@
 import os
-import unittest
 
-from gradio import Interface, examples
+import gradio as gr
 
 os.environ["GRADIO_ANALYTICS_ENABLED"] = "False"
 
 
-class TestProcessExamples(unittest.TestCase):
+class TestExamples:
+    def test_handle_single_input(self):
+        examples = gr.Examples(["hello", "hi"], gr.Textbox())
+        assert examples.processed_examples == [["hello"], ["hi"]]
+
+        examples = gr.Examples([["hello"]], gr.Textbox())
+        assert examples.processed_examples == [["hello"]]
+
+        examples = gr.Examples(["test/test_files/bus.png"], gr.Image())
+        assert examples.processed_examples == [[gr.media_data.BASE64_IMAGE]]
+
+    def test_handle_multiple_inputs(self):
+        examples = gr.Examples(
+            [["hello", "test/test_files/bus.png"]], [gr.Textbox(), gr.Image()]
+        )
+        assert examples.processed_examples == [["hello", gr.media_data.BASE64_IMAGE]]
+
+    def test_handle_directory(self):
+        examples = gr.Examples("test/test_files/images", gr.Image())
+        assert examples.processed_examples == [
+            [gr.media_data.BASE64_IMAGE],
+            [gr.media_data.BASE64_IMAGE],
+        ]
+
+    def test_handle_directory_with_log_file(self):
+        examples = gr.Examples(
+            "test/test_files/images_log", [gr.Image(label="im"), gr.Text()]
+        )
+        assert examples.processed_examples == [
+            [gr.media_data.BASE64_IMAGE, "hello"],
+            [gr.media_data.BASE64_IMAGE, "hi"],
+        ]
+
+
+class TestExamplesDataset:
+    def test_no_headers(self):
+        examples = gr.Examples("test/test_files/images_log", [gr.Image(), gr.Text()])
+        assert examples.dataset.headers == []
+
+    def test_all_headers(self):
+        examples = gr.Examples(
+            "test/test_files/images_log",
+            [gr.Image(label="im"), gr.Text(label="your text")],
+        )
+        assert examples.dataset.headers == ["im", "your text"]
+
+    def test_some_headers(self):
+        examples = gr.Examples(
+            "test/test_files/images_log", [gr.Image(label="im"), gr.Text()]
+        )
+        assert examples.dataset.headers == ["im", ""]
+
+
+class TestProcessExamples:
     def test_process_example(self):
-        io = Interface(lambda x: "Hello " + x, "text", "text", examples=[["World"]])
+        io = gr.Interface(lambda x: "Hello " + x, "text", "text", examples=[["World"]])
         prediction = io.examples_handler.process_example(0)
-        self.assertEquals(prediction[0], "Hello World")
+        assert prediction[0] == "Hello World"
 
     def test_caching(self):
-        io = Interface(
+        io = gr.Interface(
             lambda x: "Hello " + x,
             "text",
             "text",
@@ -23,8 +75,4 @@ class TestProcessExamples(unittest.TestCase):
         io.examples_handler.cache_interface_examples()
         prediction = io.examples_handler.load_from_cache(1)
         io.close()
-        self.assertEquals(prediction[0], "Hello Dunya")
-
-
-if __name__ == "__main__":
-    unittest.main()
+        assert prediction[0] == "Hello Dunya"

test/test_files/images_log/log.csv

@@ -0,0 +1,3 @@
+im,text
+im/bus.png,hello
+im/bus_copy.png,hi