diff --git a/gnssanalysis/gn_download.py b/gnssanalysis/gn_download.py
index 0e2be73..7464cb4 100644
--- a/gnssanalysis/gn_download.py
+++ b/gnssanalysis/gn_download.py
@@ -429,7 +429,7 @@ def generate_product_filename(
 def check_whether_to_download(
     filename: str,
     download_dir: _Path,
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> Union[_Path, None]:
     """Determine whether to download given file (filename) to the desired location (download_dir) based on whether it is
     already present and what action to take if it is (if_file_present)
@@ -512,7 +512,7 @@ def attempt_url_download(
     url: str,
     filename: str = None,
     type_of_file: str = None,
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> Union[_Path, None]:
     """Attempt download of file given URL (url) to chosen location (download_dir)
 
@@ -774,7 +774,7 @@ def download_file_from_cddis(
 def download_multiple_files_from_cddis(
     files: List[str],
     ftp_folder: str,
-    output_folder: _Path
+    output_folder: _Path,
 ) -> None:
     """Downloads multiple files in a single folder from cddis in a thread pool.
 
@@ -916,7 +916,7 @@ def download_product_from_cddis(
 def download_iau2000_file(
     download_dir: _Path,
     start_epoch: _datetime,
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> Union[_Path, None]:
     """Download relevant IAU2000 file from CDDIS or IERS based on start_epoch of data
 
@@ -973,7 +973,7 @@ def download_iau2000_file(
 def download_atx(
     download_dir: _Path,
     reference_frame: str = "IGS20",
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> Union[_Path, None]:
     """Download the ATX file necessary for running the PEA provided the download directory (download_dir)
 
@@ -1015,7 +1015,7 @@ def download_atx(
 
 def download_satellite_metadata_snx(
     download_dir: _Path,
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> Union[_Path, None]:
     """Download the most recent IGS satellite metadata file
 
@@ -1036,7 +1036,7 @@ def download_satellite_metadata_snx(
 
 def download_yaw_files(
     download_dir: _Path,
-    if_file_present: str = "prompt_user"
+    if_file_present: str = "prompt_user",
 ) -> List[_Path]:
     """Download yaw rate / bias files needed to for Ginan's PEA