PyExcelerate

Accelerated Excel XLSX writing library for Python

Authors: Kevin Wang and Kevin Zhang
Copyright 2015 Kevin Wang, Kevin Zhang. Portions copyright Google, Inc.
License: Simplified BSD License
Source repository
PyPI page

Description

PyExcelerate is a Python for writing Excel-compatible XLSX spreadsheet files, with an emphasis on speed.

Benchmarks

Benchmark code located in pyexcelerate/tests/benchmark.py
Ubuntu 12.04 LTS, Core i5-3450, 8GB DDR3, Python 2.7.3

|          TEST_NAME          | NUM_ROWS | NUM_COLS | TIME_IN_SECONDS |
|-----------------------------|----------|----------|-----------------|
| pyexcelerate value fastest  |     1000 |      100 |            0.47 |
| pyexcelerate value faster   |     1000 |      100 |            0.51 |
| pyexcelerate value fast     |     1000 |      100 |            1.53 |
| xlsxwriter value            |     1000 |      100 |            0.84 |
| openpyxl                    |     1000 |      100 |            2.74 |
| pyexcelerate style cheating |     1000 |      100 |            1.23 |
| pyexcelerate style fastest  |     1000 |      100 |            2.40 |
| pyexcelerate style faster   |     1000 |      100 |            2.75 |
| pyexcelerate style fast     |     1000 |      100 |            6.15 |
| xlsxwriter style cheating   |     1000 |      100 |            1.21 |
| xlsxwriter style            |     1000 |      100 |            4.85 |
| openpyxl                    |     1000 |      100 |            6.32 |

* cheating refers to pregeneration of styles

Installation

PyExcelerate is supported on Python 2.7, 3.4, 3.5, 3.6, 3.7, and 3.8.

pip install pyexcelerate

Usage

Writing bulk data

Fastest

from pyexcelerate import Workbook

data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]] # data is a 2D array

wb = Workbook()
wb.new_sheet("sheet name", data=data)
wb.save("output.xlsx")

Writing bulk data to a range

PyExcelerate also permits you to write data to ranges directly, which is faster than writing cell-by-cell. If writing a Pandas DataFrame, see the note on compatibility.

Fastest

from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("test", data=[[1, 2], [3, 4]])
wb.save("output.xlsx")

Fast

from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("test")
ws.range("B2", "C3").value = [[1, 2], [3, 4]]
wb.save("output.xlsx")

Writing cell data

Faster

from datetime import datetime
from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_cell_value(1, 1, 15) # a number
ws.set_cell_value(1, 2, 20)
ws.set_cell_value(1, 3, "=SUM(A1,B1)") # a formula
ws.set_cell_value(1, 4, datetime.now()) # a date
wb.save("output.xlsx")

Fast

from datetime import datetime
from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws[1][1].value = 15 # a number
ws[1][2].value = 20
ws[1][3].value = "=SUM(A1,B1)" # a formula
ws[1][4].value = datetime.now() # a date
wb.save("output.xlsx")

Selecting cells by name

from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.cell("A1").value = 12
wb.save("output.xlsx")

Merging cells

from pyexcelerate import Workbook

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws[1][1].value = 15
ws.range("A1", "B1").merge()
wb.save("output.xlsx")

Styling cells

Styling cells causes non-negligible overhead. It will increase your execution time (up to 10x longer if done improperly!). Only style cells if absolutely necessary.

Fastest

from pyexcelerate import Workbook, Color, Style, Font, Fill, Format
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_cell_value(1, 1, 1)
ws.set_cell_style(1, 1, Style(font=Font(bold=True)))
ws.set_cell_style(1, 1, Style(font=Font(italic=True)))
ws.set_cell_style(1, 1, Style(font=Font(underline=True)))
ws.set_cell_style(1, 1, Style(font=Font(strikethrough=True)))
ws.set_cell_style(1, 1, Style(fill=Fill(background=Color(255,0,0,0))))
ws.set_cell_value(1, 2, datetime.now())
ws.set_cell_style(1, 1, Style(format=Format('mm/dd/yy')))
wb.save("output.xlsx")

Note that in this example, subsequent calls to set_cell_style() override the previous styles and they are not merged in. To have a combined style, create a single Style object with multiple properties, for example

ws.set_cell_style(1, 1, Style(font=Font(bold=True), format=Format('mm/dd/yy')))

Faster

from pyexcelerate import Workbook, Color
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_cell_value(1, 1, 1)
ws.get_cell_style(1, 1).font.bold = True
ws.get_cell_style(1, 1).font.italic = True
ws.get_cell_style(1, 1).font.underline = True
ws.get_cell_style(1, 1).font.strikethrough = True
ws.get_cell_style(1, 1).fill.background = Color(0, 255, 0, 0)
ws.set_cell_value(1, 2, datetime.now())
ws.get_cell_style(1, 1).format.format = 'mm/dd/yy'
wb.save("output.xlsx")

Fast

from pyexcelerate import Workbook, Color
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws[1][1].value = 1
ws[1][1].style.font.bold = True
ws[1][1].style.font.italic = True
ws[1][1].style.font.underline = True
ws[1][1].style.font.strikethrough = True
ws[1][1].style.fill.background = Color(0, 255, 0, 0)
ws[1][2].value = datetime.now()
ws[1][2].style.format.format = 'mm/dd/yy'
wb.save("output.xlsx")

Note that .style.format.format's repetition is due to planned support for conditional formatting and other related features. The formatting syntax may be improved in the future.

Styling ranges

from pyexcelerate import Workbook, Color
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("test")
ws.range("A1","C3").value = 1
ws.range("A1","C1").style.font.bold = True
ws.range("A2","C3").style.font.italic = True
ws.range("A3","C3").style.fill.background = Color(255, 0, 0, 0)
ws.range("C1","C3").style.font.strikethrough = True

Styling rows

A simpler (and faster) way to style an entire row.

Fastest

from pyexcelerate import Workbook, Color, Style, Fill
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_row_style(1, Style(fill=Fill(background=Color(255,0,0,0))))
wb.save("output.xlsx")

Faster

from pyexcelerate import Workbook, Color
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.get_row_style(1).fill.background = Color(255, 0, 0)
wb.save("output.xlsx")

Fast

from pyexcelerate import Workbook, Color
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws[1].style.fill.background = Color(255, 0, 0)
wb.save("output.xlsx")

Styling columns

Fastest

from pyexcelerate import Workbook, Color, Style, Fill
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_col_style(1, Style(fill=Fill(background=Color(255,0,0,0))))
wb.save("output.xlsx")

Available style attributes

Consistent with the implementation patterns above, the following style parameters are available:

ws[1][1].style.font.bold = True
ws[1][1].style.font.italic = True
ws[1][1].style.font.underline = True
ws[1][1].style.font.strikethrough = True
ws[1][1].style.font.color = Color(255, 0, 255)
ws[1][1].style.fill.background = Color(0, 255, 0)
ws[1][1].style.alignment.vertical = 'top'
ws[1][1].style.alignment.horizontal = 'right'
ws[1][1].style.alignment.rotation = 90
ws[1][1].style.alignment.wrap_text = True
ws[1][1].style.borders.top.color = Color(255, 0, 0)
ws[1][1].style.borders.right.style = '-.'
ws[1][1].style.data_type = DataTypes.INLINE_STRING
ws[1][1].style.quote_prefix = True

Each attribute also has constructors for implementing via set_cell_style().

The following border styles are available: .-, ..-, --, .., =, ., medium -., medium -.., medium --, /-., _

Setting row heights and column widths

Row heights and column widths are set using the size attribute in Style. Appropriate values are:

-1 for auto-fit
0 for hidden
Any other value for the appropriate size.

For example, to hide column B:

from pyexcelerate import Workbook, Color, Style, Fill
from datetime import datetime

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws.set_col_style(2, Style(size=0))
wb.save("output.xlsx")

Linked styles

PyExcelerate supports using style objects instead manually setting each attribute as well. This permits you to modify the style at a later time.

from pyexcelerate import Workbook, Font

wb = Workbook()
ws = wb.new_sheet("sheet name")
ws[1][1].value = 1
font = Font(bold=True, italic=True, underline=True, strikethrough=True)
ws[1][1].style.font = font
wb.save("output.xlsx")

Pandas DataFrames

PyExcelerate does not support directly passing a Pandas DataFrame as the data argument to a new worksheet. If the sheet does not require having the headers rendered, the most efficient solution is:

ws = wb.new_sheet("sheet name", data=df.values.tolist())

Note that the conversion .tolist() is faster as PyExcelerate has some optimizations surrounding data that's provided in lists. If the sheet needs to have headers rendered, consider asking the Pandas maintainers to integrate PyExcelerate, use a transformation function, or convert your DataFrame to a list with the headers included.

Packaging with PyInstaller

PyInstaller is the only packager officially supported by PyExcelerate. Copy hook-pyexcelerate.Writer.py to your PyInstaller hooks directory.

Support

Please use the GitHub Issue Tracker and pull request system to report bugs/issues and submit improvements/changes, respectively. Pull requests must be based against the dev branch - if not, we will reject the PR and ask you to rebase against the correct branch. All nontrivial changes to code should be accompanied by a test when appropriate. We use the Nose testing framework.