Merge pull request !10 from WeidenthalerMatthias/feature.isfile

README.md

@@ -62,6 +62,15 @@ with s3_fs.open('s3://csst-prod/gaia/test/requirements.txt', s3_options=s3_optio
     file.write("CSST")
 ```
 
+### Check if the given file path exists
+```python
+from csst_fs import fs
+# local or on s3, depending on the given path
+fs.isfile('requirements.txt')
+fs.isfile('s3://csst-prod/test.txt')
+fs.isfile('s3://csst-prod/test.txt', s3_options=s3_options)
+```
+
 ## astropy直接读写s3的写法适配
 ### fits.open
 #### 老写法

csst_fs/__init__.py

@@ -2,4 +2,5 @@ from .fits import fsspec_fits
 from .fits import fsspec_header
 from .fits import fsspec_HDUList
 from .table import fsspec_table
-from . import s3_fs
\ No newline at end of file
+from . import s3_fs
+from . import fs
\ No newline at end of file

csst_fs/fs.py

+from .s3_fs import is_s3_path
+from .s3_fs import isfile as s3_isfile
+from .local_fs import isfile as local_isfile
+
+def isfile(path: str, *args, **kwargs) -> bool:
+    if is_s3_path(path):
+        return s3_isfile(path, *args, **kwargs)
+    else:
+        return local_isfile(path, *args, **kwargs)

csst_fs/local_fs.py

+import os
+
+def isfile(path: str) -> bool:
+    return os.path.isfile(path)
+    
\ No newline at end of file

csst_fs/s3_fs.py

@@ -15,4 +15,13 @@ def info(path, bucket=None, key=None, refresh=False, version_id=None, s3_options
     return s3_fs.info(path, bucket, key, refresh, version_id)
 
 def open(file: str, mode: str='r', s3_options=load_s3_options()):
-    return open_fileobj(path=file, s3_options=s3_options, mode=mode)
\ No newline at end of file
+    return open_fileobj(path=file, s3_options=s3_options, mode=mode)
+
+def isfile(path: str, s3_options: dict=load_s3_options()) -> bool:
+    s3_fs = fsspec.filesystem('s3', **s3_options)
+    return s3_fs.isfile(path)
+    
+def is_s3_path(path: str):
+    if(path.startswith("s3")):
+        return True
+    return False