3.6 support (#1)

* Update requirements.txt

* Update python-package.yml

* specified read_excel engine

* Update python-package.yml

* Update spreadsheet_utils.py

* Update spreadsheet_utils.py

* Update spreadsheet_utils.py

* Update spreadsheet_utils.py

* updated supported versions

* Update python-package.yml

.github/workflows/python-package.yml

@@ -12,11 +12,11 @@ on:
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.6","3.7", "3.8", "3.9", "3.10", "3.11"]
 
     steps:
     - uses: actions/checkout@v3

mecsimcalc/spreadsheet_utils.py

@@ -41,7 +41,7 @@ def file_to_dataframe(file: io.BytesIO) -> pd.DataFrame:
         df = pd.read_csv(file)
     except Exception:
         try:
-            df = pd.read_excel(file)
+            df = pd.read_excel(file, engine="openpyxl")
         except Exception as e:
             raise pd.errors.ParserError("File Type Not Supported") from e
 
@@ -164,7 +164,7 @@ def print_dataframe(
         "odt",
     }:
         # convert the DataFrame to an excel file
-        df.to_excel(buf, index=False)
+        df.to_excel(buf, index=False, engine="openpyxl")
         buf.seek(0)
 
         encoded_data = (
@@ -174,7 +174,8 @@ def print_dataframe(
 
     # if the file type does not match an alias of excel, convert the DataFrame to a csv file
     else:
-        df.to_csv(buf, index=False)
+        csv_str = df.to_csv(index=False)
+        buf.write(csv_str.encode())
         buf.seek(0)
 
         encoded_data = "data:text/csv;base64," + base64.b64encode(buf.read()).decode()

requirements.txt

@@ -1,4 +1,4 @@
-pillow ~= 9.0
-pandas ~= 1.3
-matplotlib ~= 3.5
-openpyxl
+pillow
+pandas >= 1.1.5
+matplotlib
+openpyxl

setup.py

@@ -25,6 +25,7 @@
     classifiers=[
         "Development Status :: 3 - Alpha",
         "Intended Audience :: Developers",
+        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",