Get list of files in a folder

Tonight's tip shows how to perform another basic task using a basic Python script. Using Python IDLE 3.4.2, we'll get a list of all of the Excel files in this directory:

Open Python IDLE and import the glob module.

>>> import glob

Then use this command to generate a list of the files with particular extension in the specified directory. >>> glob.glob("C:\FooFolder\python\*.xlsx")

These results are returned:

Accessing Excel files with OpenPyXL

Here's a quick rundown of how to access an Excel file using Python and get a list of its worksheet names.

OpenPyXL is a module that will allow you to work with Excel spreadsheets in Python. In order to import it (I'm using Python 3.4.2 in this example) . . . go to the folder for the Python software containing scripts and open the Windows command prompt. Enter the command:

pip install openpyxl==2.1.4

After the module is imported, go to Python IDLE, and enter the command:

>>> import openpyxl

We'll review this spreadsheet:

Name the the Excel workbook with the openpyxl.load function, specifying the full path to the Excel file:

>>> wb = openpyxl.load_workbook('C:\FooFolder\python\BattingPost.xlsx')

After the workbook is accessed use this function to generate a list of the names of the worksheets used in the workbook: >>> wb.get_sheet_names()

As shown here we get the following results:

Reading a .csv file with Python's csv module

Here's a follow-up to the Tip of the Night for February 2, 2019, which explained how to read comma separated values in a text file. Python includes a .csv module which can be used to read a file with the .csv extension saved from Excel.

To activate the module enter this line:

>>> import csv

open the file and designate it with a name >>> with open ("C:\FooFolder\Python\cities.csv", newline="") as f:

. . . then specify the delimiter for the .csv file r = csv.reader(f, delimiter=",")

. . . finally display the contents in a delimited list: for row in r: print(row)

['Chicago', 'New York', 'Los Angeles', 'Houston'] ['Springfield', 'Buffalo', 'San Francisco', 'Austin'] ['Joliet', 'Albany', 'San Diego', 'El Paso'] >>>

The csv module has multiple functions and can also be used to write data to .csv files.