Python Programming/Excel

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Python has multiple 3rd party libraries for reading and writing Microsoft Excel spreadsheet files, including .xls and .xlsx.

For working with .xls files, there is xlrd for reading and xlwt for writing.

For working with .xlsx files, there is xlrd for reading, openpyxl for reading and writing, and XlsxWriter and PyExcelerate for writing.

To interact with the Excel application and create Python-based add-ins: xlwings, xlOil, PyXLL (commercial).

xlrd[edit | edit source]

Supports reading .xls Excel files. Support for .xlsx files was removed in xlrd version 2.0.0 from Dec 2020 due to security concerns, but is still available in xlrd version 1.2.0 from Dec 2018. License: BSD.

Example:

import xlrd
workbook = xlrd.open_workbook("MySpreadsheet.xls")
#for sheet in workbook.sheets(): # Loads all the sheets, unlike workbook.sheet_names()
for sheetName in workbook.sheet_names(): # Sheet iteration by name
  print("Sheet name:", sheetName)
  sheet = workbook.sheet_by_name(sheetName)
  for rowno in range(sheet.nrows):
    for colno in range(sheet.ncols):
      cell = sheet.cell(rowno, colno)
      print(str(cell.value)) # Output as a string
      if cell.ctype == xlrd.XL_CELL_DATE:
        dateTuple = xlrd.xldate_as_tuple(cell.value, workbook.datemode)
        print(dateTuple) # E.g. (2017, 1, 1, 0, 0, 0)
        mydate = xlrd.xldate.xldate_as_datetime(cell.value, workbook.datemode)
        print(mydate) # In xlrd 0.9.3
      print()
    
for sheetno in range(workbook.nsheets): # Sheet iteration by index
  sheet = workbook.sheet_by_index(sheetno)
  print("Sheet name:", sheet.name)
  for notekey in sheet.cell_note_map: # In xlrd 0.7.2
    print("Note AKA comment text:", sheet.cell_note_map[notekey].text)
  
print(xlrd.formula.colname(1)) # Column name such as A or AD, here 'B'

Links:

xlwt[edit | edit source]

Supports writing .xls files. License: BSD.

Links:

openpyxl[edit | edit source]

Supports reading and writing .xlsx Excel files. Does not support .xls files. License: MIT.

Reading a workbook:

from openpyxl import load_workbook
workbook = load_workbook("MyNewWorkbook.xlsx")
for worksheet in workbook.worksheets:
  print("==%s==" % worksheet.title)
  for row in worksheet: # For each cell in each row
    for cell in row:
      print(cell.row, cell.column, cell.value) # E.g. 1 A Value
  for cell in worksheet["A"]: # For each cell in column A
    print(cell.value)
  print(worksheet["A1"].value) # A single cell
  print(worksheet.cell(column=1, row=1).value) # A1 value as well

Creating a new workbook:

from openpyxl import Workbook
workbook = Workbook()
worksheet = workbook.worksheets[0]
worksheet['A1'] = 'String value'
worksheet['A2'] = 42 # Numerical value
worksheet.cell(row=3, column=1).value = "New A3 Value"
workbook.save("MyNewWorkbook.xlsx") # Overrides if it exists

Changing an existing workbook:

from openpyxl import load_workbook
workbook_name = 'MyWorkbook.xlsx'
workbook = load_workbook(workbook_name)
worksheet = workbook.worksheets[0]
worksheet['A1'] = "String value"
workbook.save(workbook_name)

Links:

XlsxWriter[edit | edit source]

Supports writing of .xlsx files. License: BSD.

Links:

PyExcelerate[edit | edit source]

Supports writing .xlsx files. License: BSD.

Links:

xlutils[edit | edit source]

Supports various operations and queries on .xls files; depends on xlrd and xlwt. License: MIT.

Links:

xlOil[edit | edit source]

Supports creation of Python-based Excel add-ins. Requires Python 3.6 or later; requires Excel 2010 or later installed. Supports: global and local scope worksheet functions, ribbon customisation, custom task panes, RTD/async functions, numpy, matplotlib, pandas, jupyter. Low overhead function calls due to use of the Excel's C-API and embedded in-process Python

Examples:

Create a function to add one day to a date:

import datetime as dt
@xloil.func
def pyTestDate(x: dt.datetime) -> dt.datetime:
    return x + dt.timedelta(days=1)

Create a function which give a live ticking clock in an cell (uses RTD):

@xloil.func
async def pyTestAsyncGen(secs):
    while True:
        await asyncio.sleep(secs)
        yield datetime.datetime.now()

Links:

pywin32[edit | edit source]

Supports access to Windows applications via Windows Component Object Model (COM). Thus, on Windows, if Excel is installed, PyWin32 lets you call it from Python and let it do various things. You can install PyWin32 by downloading a .exe installer from SourceForge, where it is currently hosted.

Links:

External links[edit | edit source]