Change pandas ExcelWriter engine to openpyxl.

-Eliminates need for `XlsxWriter` package.

FlowCal/excel_ui.py

@@ -96,6 +96,7 @@
 from matplotlib import pyplot as plt
 import numpy as np
 import pandas as pd
+import openpyxl
 
 import FlowCal.io
 import FlowCal.plot
@@ -183,7 +184,7 @@ def write_workbook(filename, table_list, column_width=None):
         Tables to be saved as individual sheets in the Excel table. Each
         tuple contains two values: the name of the sheet to be saved as a
         string, and the contents of the table as a DataFrame.
-    column_width: int, optional
+    column_width: int or float, optional
         The column width to use when saving the spreadsheet. If None,
         calculate width automatically from the maximum number of characters
         in each column.
@@ -216,7 +217,7 @@ def write_workbook(filename, table_list, column_width=None):
         pass
 
     # Generate output writer object
-    writer = pd.ExcelWriter(filename, engine='xlsxwriter')
+    writer = pd.ExcelWriter(filename, engine='openpyxl')
 
     # Write tables
     for sheet_name, df in table_list:
@@ -225,21 +226,18 @@ def write_workbook(filename, table_list, column_width=None):
         # Write to an Excel sheet
         df.to_excel(writer, sheet_name=sheet_name, index=False)
         # Set column width
-        if column_width is None:
-            for i, (col_name, column) in enumerate(six.iteritems(df)):
+        for i, (col_name, column) in enumerate(six.iteritems(df)):
+            if column_width is None:
                 # Get the maximum number of characters in a column
                 max_chars_col = column.astype(str).str.len().max()
                 max_chars_col = max(len(col_name), max_chars_col)
-                # Write width
-                writer.sheets[sheet_name].set_column(
-                    i,
-                    i,
-                    width=1.*max_chars_col)
-        else:
-            writer.sheets[sheet_name].set_column(
-                0,
-                len(df.columns) - 1,
-                width=column_width)
+                width = float(max_chars_col)
+            else:
+                width = float(column_width)
+
+            # Write width
+            col_letter = openpyxl.utils.get_column_letter(i+1)
+            writer.sheets[sheet_name].column_dimensions[col_letter].width = width
 
     # Write excel file
     writer.save()

doc/getting_started/install_python.rst

@@ -19,7 +19,7 @@ Alternatively, download ``FlowCal`` from `here <https://github.com/taborlab/Flow
 * ``scikit-learn`` (>=0.16.0)
 * ``pandas`` (>=0.16.1)
 * ``xlrd`` (>=0.9.2)
-* ``XlsxWriter`` (>=0.5.2)
+* ``openpyxl`` (>=2.4.1)
 
 If you have ``pip``, a ``requirements.txt`` file is provided, such that the required packages can be installed by running::
 
@@ -52,4 +52,4 @@ Again, some users may need to precede the previous commands with ``sudo``.
 
 		sudo pip install --upgrade pip
 
-	After this, you may install ``FlowCal`` by following the steps above.
+	After this, you may install ``FlowCal`` by following the steps above.

requirements.txt

@@ -8,4 +8,4 @@ scikit-image>=0.10.0
 scikit-learn>=0.16.0
 pandas>=0.16.1
 xlrd>=0.9.2
-XlsxWriter>=0.5.2
+openpyxl>=2.4.1

setup.py

@@ -95,7 +95,7 @@ def find_version(file_path):
                       'scikit-learn>=0.16.0',
                       'pandas>=0.16.1',
                       'xlrd>=0.9.2',
-                      'XlsxWriter>=0.5.2'],
+                      'openpyxl>=2.4.1'],
 
     # List additional groups of dependencies here (e.g. development
     # dependencies). You can install these using the following syntax,