Category: Python Answers

Sometimes, we want to simulate keydown with Python.

In this article, we’ll look at how to simulate keydown with Python.

How to simulate keydown with Python?

To simulate keydown with Python, we can use the pykeyboard library.

To install it, we run

pip install pykeyboard

Then we use it by writing

from pykeyboard import PyKeyboard
from time import sleep

keyboard = PyKeyboard()
keyboard.press_key('s')
sleep(5)
keyboard.release_key('s')

We call keyboard.press_key to press the s key.

And then we call release_key to release the s key.

Conclusion

To simulate keydown with Python, we can use the pykeyboard library.

Sometimes, we want to plot a horizontal line using matplotlib in Python.

In this article, we’ll look at how to plot a horizontal line using matplotlib in Python.

How to plot a horizontal line using matplotlib in Python?

To plot a horizontal line using matplotlib in Python, we can use the axhline method.

For instance, we write

import matplotlib.pyplot as plt

plt.axhline(y=0.5, color='r', linestyle='-')
plt.show()

to call axhline with the y value for the horizontal line.

And we set the color and linestyle for the line.

Then we call show to show the line.

The line y = 0.5 is then plotted.

Conclusion

To plot a horizontal line using matplotlib in Python, we can use the axhline method.

Sometimes, we want to write to a CSV line by line with Python.

In this article, we’ll look at how to write to a CSV line by line with Python.

How to write to a CSV line by line with Python?

To write to a CSV line by line with Python, we can use the CSV writer.

For instance, we write

import csv

with open(<path to output_csv>, "wb") as csv_file:
        writer = csv.writer(csv_file, delimiter=',')
        for line in data:
            writer.writerow(line)

to call open to open the csv file with write permission and as a binary file.

Then we call csv.writer with the opened csv_file to create a writer object.

We set the delimiter to the delimiter of the row items.

And then we add a for loop that calls writerow to write the line to the csv.

Conclusion

To write to a CSV line by line with Python, we can use the CSV writer.

Sometimes, we want to replace values in list using Python.

In this article, we’ll look at how to replace values in list using Python.

How to replace values in list using Python?

To replace values in list using Python, we can use list comprehension.

For instance, we write

new_items = [x if x % 2 else None for x in items]

to loop through the items in list item and return value x in items if it’s odd and None otherwise and put them in the new list.

Conclusion

To replace values in list using Python, we can use list comprehension.

Sometimes, we want to read the exif data for an image in Python.

In this article, we’ll look at how to read the exif data for an image in Python.

How to read the exif data for an image in Python?

To read the exif data for an image in Python, we can use PIL.

For instance, we write

from PIL import Image, ExifTags

img = Image.open("sample.jpg")
img_exif = img.getexif()

if img_exif is None:
    print('Sorry, image has no exif data.')
else:
    for key, val in img_exif.items():
        if key in ExifTags.TAGS:
            print(f'{ExifTags.TAGS[key]}:{val}')

to open the image with Image.open.

Then we call img.getexif to get the exif data from the image.

Next, we loop through the img_exif dict with a for loop.

We get the key and value with items.

Conclusion

To read the exif data for an image in Python, we can use PIL.