Use `requests` instead of `wget` in `convert_from_ckpt.py` (#2168)

-- This commit adopts `requests` in place of `wget` to fetch config `.yaml`
   files as part of `load_pipeline_from_original_stable_diffusion_ckpt` API.
-- This was done because in Windows PowerShell one needs to explicitly ensure
   that `wget` binary is part of the PATH variable. If not present, this leads
   to the code not being able to download the `.yaml` config file.

Signed-off-by: Abhishek Varma <abhishek@nod-labs.com>
Co-authored-by: Abhishek Varma <abhishek@nod-labs.com>

src/diffusers/pipelines/stable_diffusion/convert_from_ckpt.py

@@ -20,6 +20,7 @@ import tempfile
 
 import torch
 
+import requests
 from diffusers import (
     AutoencoderKL,
     DDIMScheduler,
@@ -860,11 +861,10 @@ def load_pipeline_from_original_stable_diffusion_ckpt(
             if key_name in checkpoint and checkpoint[key_name].shape[-1] == 1024:
                 if not os.path.isfile("v2-inference-v.yaml"):
                     # model_type = "v2"
-                    os.system(
-                        "wget -P"
+                    r = requests.get(
                         " https://raw.githubusercontent.com/Stability-AI/stablediffusion/main/configs/stable-diffusion/v2-inference-v.yaml"
-                        f" -O {original_config_file}"
                     )
+                    open(original_config_file, "wb").write(r.content)
 
                 if global_step == 110000:
                     # v2.1 needs to upcast attention
@@ -872,11 +872,10 @@ def load_pipeline_from_original_stable_diffusion_ckpt(
             else:
                 if not os.path.isfile("v1-inference.yaml"):
                     # model_type = "v1"
-                    os.system(
-                        "wget"
+                    r = requests.get(
                         " https://raw.githubusercontent.com/CompVis/stable-diffusion/main/configs/stable-diffusion/v1-inference.yaml"
-                        f" -O {original_config_file}"
                     )
+                    open(original_config_file, "wb").write(r.content)
 
         original_config = OmegaConf.load(original_config_file)