Changed tutorials' pip searching

Summary:
### Generalise tutorials' pip searching:
## Required Information:
This diff contains changes to several PyTorch3D tutorials.

**Purpose of this diff:**
Replace the current installation code with a more streamlined approach that tries to install the wheel first and falls back to installing from source if the wheel is not found.

**Why this diff is required:**
This diff makes it easier to cope with new PyTorch releases and reduce the need for manual intervention, as the current process involves checking the version of PyTorch in Colab and building a new wheel if it doesn't match the expected version, which generates additional work each time there is a a new PyTorch version in Colab.

**Changes:**
Before:
```
    if torch.__version__.startswith("2.1.") and sys.platform.startswith("linux"):
        # We try to install PyTorch3D via a released wheel.
        pyt_version_str=torch.__version__.split("+")[0].replace(".", "")
        version_str="".join([
            f"py3{sys.version_info.minor}_cu",
            torch.version.cuda.replace(".",""),
            f"_pyt{pyt_version_str}"
        ])
        !pip install fvcore iopath
        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html
    else:
        # We try to install PyTorch3D from source.
        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'
```
After:
```
    pyt_version_str=torch.__version__.split("+")[0].replace(".", "")
    version_str="".join([
        f"py3{sys.version_info.minor}_cu",
        torch.version.cuda.replace(".",""),
        f"_pyt{pyt_version_str}"
    ])
    !pip install fvcore iopath
    if sys.platform.startswith("linux"):
      # We try to install PyTorch3D via a released wheel.
      !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html
      pip_list = !pip freeze
      need_pytorch3d = not any(i.startswith("pytorch3d==") for  i in pip_list)

    if need_pytorch3d:
        # We try to install PyTorch3D from source.
        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'
```

Reviewed By: bottler

Differential Revision: D55431832

fbshipit-source-id: a8de9162470698320241ae8401427dcb1ce17c37

docs/tutorials/bundle_adjustment.ipynb

@@ -83,25 +83,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/camera_position_optimization_with_differentiable_rendering.ipynb

@@ -70,25 +70,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/dataloaders_ShapeNetCore_R2N2.ipynb

@@ -45,25 +45,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/deform_source_mesh_to_target_mesh.ipynb

@@ -84,25 +84,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/fit_simple_neural_radiance_field.ipynb

@@ -50,25 +50,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/fit_textured_mesh.ipynb

@@ -62,25 +62,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/fit_textured_volume.ipynb

@@ -41,25 +41,31 @@
     "import os\n",
     "import sys\n",
     "import torch\n",
+    "import subprocess\n",
     "need_pytorch3d=False\n",
     "try:\n",
     "    import pytorch3d\n",
     "except ModuleNotFoundError:\n",
     "    need_pytorch3d=True\n",
     "if need_pytorch3d:\n",
-    "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-    "        # We try to install PyTorch3D via a released wheel.\n",
-    "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-    "        version_str=\"\".join([\n",
-    "            f\"py3{sys.version_info.minor}_cu\",\n",
-    "            torch.version.cuda.replace(\".\",\"\"),\n",
-    "            f\"_pyt{pyt_version_str}\"\n",
-    "        ])\n",
-    "        !pip install fvcore iopath\n",
+    "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+    "    version_str=\"\".join([\n",
+    "        f\"py3{sys.version_info.minor}_cu\",\n",
+    "        torch.version.cuda.replace(\".\",\"\"),\n",
+    "        f\"_pyt{pyt_version_str}\"\n",
+    "    ])\n",
+    "    !pip install fvcore iopath\n",
+    "    if sys.platform.startswith(\"linux\"):\n",
+    "        print(\"Trying to install wheel for PyTorch3D\")\n",
     "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-    "    else:\n",
-    "        # We try to install PyTorch3D from source.\n",
-    "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+    "        pip_list = !pip freeze\n",
+    "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+    "    if need_pytorch3d:\n",
+    "        print(f\"failed to find/install wheel for {version_str}\")\n",
+    "if need_pytorch3d:\n",
+    "    print(\"Installing PyTorch3D from source\")\n",
+    "    !pip install ninja\n",
+    "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
    ]
   },
   {

docs/tutorials/implicitron_config_system.ipynb

@@ -72,25 +72,31 @@
         "import os\n",
         "import sys\n",
         "import torch\n",
+        "import subprocess\n",
         "need_pytorch3d=False\n",
         "try:\n",
         "    import pytorch3d\n",
         "except ModuleNotFoundError:\n",
         "    need_pytorch3d=True\n",
         "if need_pytorch3d:\n",
-        "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-        "        # We try to install PyTorch3D via a released wheel.\n",
-        "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-        "        version_str=\"\".join([\n",
-        "            f\"py3{sys.version_info.minor}_cu\",\n",
-        "            torch.version.cuda.replace(\".\",\"\"),\n",
-        "            f\"_pyt{pyt_version_str}\"\n",
-        "        ])\n",
-        "        !pip install fvcore iopath\n",
+        "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+        "    version_str=\"\".join([\n",
+        "        f\"py3{sys.version_info.minor}_cu\",\n",
+        "        torch.version.cuda.replace(\".\",\"\"),\n",
+        "        f\"_pyt{pyt_version_str}\"\n",
+        "    ])\n",
+        "    !pip install fvcore iopath\n",
+        "    if sys.platform.startswith(\"linux\"):\n",
+        "        print(\"Trying to install wheel for PyTorch3D\")\n",
         "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-        "    else:\n",
-        "        # We try to install PyTorch3D from source.\n",
-        "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+        "        pip_list = !pip freeze\n",
+        "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+        "    if need_pytorch3d:\n",
+        "        print(f\"failed to find/install wheel for {version_str}\")\n",
+        "if need_pytorch3d:\n",
+        "    print(\"Installing PyTorch3D from source\")\n",
+        "    !pip install ninja\n",
+        "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
       ]
     },
     {

docs/tutorials/implicitron_volumes.ipynb

@@ -66,25 +66,31 @@
         "import os\n",
         "import sys\n",
         "import torch\n",
+        "import subprocess\n",
         "need_pytorch3d=False\n",
         "try:\n",
         "    import pytorch3d\n",
         "except ModuleNotFoundError:\n",
         "    need_pytorch3d=True\n",
         "if need_pytorch3d:\n",
-        "    if torch.__version__.startswith(\"2.2.\") and sys.platform.startswith(\"linux\"):\n",
-        "        # We try to install PyTorch3D via a released wheel.\n",
-        "        pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
-        "        version_str=\"\".join([\n",
-        "            f\"py3{sys.version_info.minor}_cu\",\n",
-        "            torch.version.cuda.replace(\".\",\"\"),\n",
-        "            f\"_pyt{pyt_version_str}\"\n",
-        "        ])\n",
-        "        !pip install fvcore iopath\n",
+        "    pyt_version_str=torch.__version__.split(\"+\")[0].replace(\".\", \"\")\n",
+        "    version_str=\"\".join([\n",
+        "        f\"py3{sys.version_info.minor}_cu\",\n",
+        "        torch.version.cuda.replace(\".\",\"\"),\n",
+        "        f\"_pyt{pyt_version_str}\"\n",
+        "    ])\n",
+        "    !pip install fvcore iopath\n",
+        "    if sys.platform.startswith(\"linux\"):\n",
+        "        print(\"Trying to install wheel for PyTorch3D\")\n",
         "        !pip install --no-index --no-cache-dir pytorch3d -f https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/{version_str}/download.html\n",
-        "    else:\n",
-        "        # We try to install PyTorch3D from source.\n",
-        "        !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
+        "        pip_list = !pip freeze\n",
+        "        need_pytorch3d = not any(i.startswith(\"pytorch3d==\") for  i in pip_list)\n",
+        "    if need_pytorch3d:\n",
+        "        print(f\"failed to find/install wheel for {version_str}\")\n",
+        "if need_pytorch3d:\n",
+        "    print(\"Installing PyTorch3D from source\")\n",
+        "    !pip install ninja\n",
+        "    !pip install 'git+https://github.com/facebookresearch/pytorch3d.git@stable'"
       ]
     },
     {