Category: Python Answers

Sometimes, we want to reset a generator object in Python.

In this article, we’ll look at how to reset a generator object in Python.

How to reset a generator object in Python?

To reset a generator object in Python, we can use the itertools.tee method.

For instance, we write

import itertools

y = gen()
y, y_backup = itertools.tee(y)
for x in y:
    print(x)
for x in y_backup:
    print(x)

to call itertools.tee with generator y to get a 2nd version of the generator.

Then we get the original value returned from the y_backup generator object.

Conclusion

To reset a generator object in Python, we can use the itertools.tee method.

Sometimes, we want to read keyboard-input with Python.

In this article, we’ll look at how to read keyboard-input with Python.

How to read keyboard-input with Python?

To read keyboard-input with Python, we can use the input function.

For instance, we write

input('Enter your input:')

to call input with the ‘Enter your input:’ prompt.

Then the input value is returned as a string when we type in something into the prompt and press enter.

Conclusion

To read keyboard-input with Python, we can use the input function.

Sometimes, we want to handle the window close event in Tkinter with Python.

In this article, we’ll look at how to handle the window close event in Tkinter with Python.

How to handle the window close event in Tkinter with Python?

To handle the window close event in Tkinter with Python, we call the root.protocol method with the 'WM_DELETE_WINDOW' event.

For instance, we write

import tkinter as tk
from tkinter import messagebox

root = tk.Tk()

def on_closing():
    if messagebox.askokcancel("Quit", "Do you want to quit?"):
        root.destroy()

root.protocol("WM_DELETE_WINDOW", on_closing)
root.mainloop()

to call root.protocole with "WM_DELETE_WINDOW" to add a close window handler.

And we specify that we use the on_closing function as the close window handler.

Therefore, when we close the window, we see a message box with title ‘Quit’ and text ‘Do you want to quit’.

And then if we confirm, then root.destroy is called to close the window.

Conclusion

To handle the window close event in Tkinter with Python, we call the root.protocol method with the 'WM_DELETE_WINDOW' event.

Sometimes, we want to use regular expression to match a multiline block of text with Python.

In this article, we’ll look at how to use regular expression to match a multiline block of text with Python.

How to use regular expression to match a multiline block of text with Python?

To use regular expression to match a multiline block of text with Python, we can use the re.compile method with the re.MULTILINE flag.

For instance, we write

re.compile(r"^(.+)\n((?:\n.+)+)", re.MULTILINE)

to create a regex that matches characters followed by newlines with the re.compile method.

We call it with re.MULTILINE flag to let us match multiline strings.

Conclusion

To use regular expression to match a multiline block of text with Python, we can use the re.compile method with the re.MULTILINE flag.

Sometimes, we want to get a frequency count based on two columns (variables) in Pandas data frame some row appears with Python.

In this article, we’ll look at how to get a frequency count based on two columns (variables) in Pandas data frame some row appears with Python.

How to get a frequency count based on two columns (variables) in Pandas data frame some row appears with Python?

To get a frequency count based on two columns (variables) in Pandas data frame some row appears with Python, we can use the size method.

For instance, we write

df.groupby(["Group", "Size"]).size()

to call groupby to group data by the Group and Size columns in the df data frame.

Then we call size to get the size of each group.

Conclusion

To get a frequency count based on two columns (variables) in Pandas data frame some row appears with Python, we can use the size method.