Format specifier missing precision error with string formatting

This is my code:

from tkinter import * def calculate(): temp = int(entry.get()) temp = 9/5*temp+32 output_label.configure(text = 'Converted: {:.lf}'.format(temp)) entry.delete(0,END) root = Tk() message_label = Label(text = 'Enter a temperature', font=('Verdana', 16)) output_label = Label(font = ('Verdana', 16)) entry = Entry(font = ('Verdana', 16), width=4) calc_button = Button(text ='ok', font=('Verdana', 16), command=calculate) message_label.grid(row=0, column=0) entry.grid(row=0, column=1) calc_button.grid(row=0, column=2) output_label.grid(row=1, column=0, columnspan=3) mainloop() 

This is the output error:

Exception in Tkinter callback Traceback (most recent call last): File "C:\Users\USER\Anaconda3\envs\nlp_course\lib\tkinter\__init__.py", line 1705, in __call__ return self.func(*args) File "<ipython-input-9-c6af4eb59ca6>", line 7, in calculate output_label.configure(text = 'Converted: {:.lf}'.format(temp)) ValueError: Format specifier missing precision 

Can someone help with this problem?

2 Answers

There is a small mistake in your format string:

'Converted: {:.lf}' 

should be

'Converted: {:.1f}' 

The only difference is that you have used l instead of 1 when specifying the float precision. 1f means that your float should be output with one decimal place.

For me, this happened with

'Converted: {:.1.f}' 

instead of the correct

'Converted: {:.1f}' 

Probably happens when the format specifier is wrong