Measure the height of a string in Tkinter Python?

In Tkinter, you can measure the height of a string using the font and metrics modules. Measuring the height of a string can be useful in a variety of scenarios, such as when you need to align text or objects within a canvas or when you need to dynamically adjust the size of a widget based on its contents.

To measure the height of a string, you first need to create a Font object using the font module. The Font object specifies the font family, font size, and font style of the text you want to measure.

Example

Below is an example of how to create a Font object −

import tkinter as tk
from tkinter.font import Font
root = tk.Tk()
# create a font object with Arial font, size 16, and bold style
font = Font(family="Arial", size=16, weight="bold")

Once you have a Font object, you can use the metrics module to measure the height of a string. The metrics module provides several methods for measuring text, including linespace, ascent, descent, and textwidth.

The linespace method returns the height of a line of text, including any extra spacing between lines. The ascent method returns the distance from the baseline to the top of the highest glyph in the font. The descent method returns the distance from the baseline to the bottom of the lowest glyph in the font. The textwidth method returns the width of a string of text in pixels.

Example

Below is an example of how to measure the height of a string using the linespace method −

import tkinter as tk
from tkinter.font import Font
root = tk.Tk()
# create a font object with Arial font, size 16, and bold style
font = Font(family="Arial", size=16, weight="bold")
# measure the height of a line of text
line_height = font.metrics("linespace")
print(line_height)

Output

When you run this code, you'll get the height of the string −

24

In this example, we create a Font object with Arial font, size 14, and bold style. We then use the metrics method to measure the height of a line of text. The height is stored in the line_height variable, which we print to the console.

You can also measure the height of a string by multiplying the line height by the number of lines in the string. To count the number of lines in a string, you can split the string into a list of lines using the splitlines() method and then count the number of elements in the list.

Example

Below is an example of how to measure the height of a multi-line string using the splitlines() method −

import tkinter as tk
from tkinter.font import Font
root = tk.Tk()

# create a font object with Arial font, size 16, and bold style
font = Font(family="Arial", size=16, weight="bold")

# create a multi-line string
text = "This is a\nmulti-line\nstring."

# measure the height of the string
line_height = font.metrics("linespace")
num_lines = len(text.splitlines())
total_height = line_height * num_lines

print(total_height)

Output

When you run this code, you'll get the height of the multi-line string −

72

In this example, we create a Font object with Arial font, size 14, and bold style. We then create a multi-line string and store it in the text variable. We measure the height of a line of text using the metrics method and store it in the line_height variable. We count the number of lines in the string using the splitlines() method and store it in the num_lines variable. Finally, we calculate the total height of the string by multiplying the line height by the number of lines and store it in the total_height variable. We then print the total height to the console.

Conclusion

In conclusion, measuring the height of a string in Tkinter can be done using the font and metrics modules. By creating a Font object and using the metrics module, you can measure the height of a line of text and the number of lines in a multi-line string. You can also measure the width of a string using the measure() method of the Font object. These measurements can be useful in a variety of scenarios, such as when you need to align text or objects within a canvas or when you need to dynamically adjust the size of a widget based on its contents.