CODEWITHSUNDEEP
pythontkintertcl
shuji
shuji

Reputation: 5

python tkinter package tk.call eval

I'm using python tkinter to run tcl in python And there are two ways to run a tcl command:

import tkinter 
root = tkinter.Tk()
root.eval("winfo exists .l0")
root.tk.call("winfo exists .l0")

They have the same meaning

But what's different? And if I haven't define a widget names .l0 and can I directly use 

child = ".l0"
child.winfo_exists()

? Because python told me "str has no attribute winfo_exists"

Upvotes: 0

Views: 1379

Answers (1)

Bryan Oakley
Bryan Oakley

Reputation: 386382

The difference is that call passes each argument to tcl as a separate word, where eval will evaluate a string by first parsing it and then executing it.

In other words, this:

root.eval("winfo exists .l0")

... is functionally identical to this:

root.tk.call("winfo", "exists", ".l0")

As for the error message 'str' object has no attribute 'winfo_exists', it means exactly that. "l0" is the name of an object in the embedded tcl interpreter, but in python "l0" is just a string and python strings don't have the attribute winfo_exists.

Upvotes: 1

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