I am making a GUI in Tkinter with Python 2.7. I have a frame with about 30 entry boxes among other things. I don't have access to the code right now, but is there a way to check if any or several of the boxes are empty so I can warn the user and ask them if they want to proceed?
Is there a way to go through each of them with a 'for' loop and check the length of each entry. Or is there a command to check if any box is empty?
You can get the content of the entry using Tkinter.Entry.get method.
Check the length of the entry using len function and get method:
if len(entry_object.get()) == 0: # empty!
# do something
or more preferably:
if not entry_object.get(): # empty! (empty string is false value)
# do something
Use for loop to check several entry widgets:
for entry in entry_list:
if not entry_object.get():
# empty!
You should populate entry_list beforehand.
Manually:
entry_list = []
entry = Entry(...)
...
entry_list.append(entry)
entry = Entry(...)
...
entry_list.append(entry)
or, using winfo_children method (to get all entries):
entry_list = [child for child in root_widget.winfo_children()
if isinstance(child, Entry)]
Related
I'm trying add/remove an item (text of checkbox) to/from a list whenever a checkbox is checked/unchecked in tkinter.
My idea was to add a command to the checkbutton, like:
cb = Checkbutton(master,...,command=some_fun)
but I cannot think of a way to define the function. I was thinking the function should contain the widget attribute cget('text'), but the problem is I have many checkboxes made with the help of a loop.
I guess the question is: how can I reference the checkbox whose state got changed and is therefore calling the function some_fun?
The way I generated the checkboxes is:
cb_identities = []
for i in range(cb_max_num):
cb = Checkbutton(frame_data,bg="white")
cb_identities.append(cb)
And then I'm dynamically changing them depending on some radiobuttons:
def fun_chck(): #shows or hides checkbuttons based on radiobutton input
data = read_data(rb_var.get())
for i in range(cb_max_num):
cbname = (cb_identities[i])
if len(data)-1 < i:
cbname.grid_forget()
else:
cbname.config(text=data[i]) #I would place some_fun here, which gets text option of checked box
cbname.grid(row=i,column=1,sticky=W)
Update! I managed with the following code for anyone interested:
cb_var_init = [0] * cb_max_num #create the initial list of inactive checkbuttons, all 0
input_params=[] #list which needs to be populated/depopulated based on checkbutton state
def get_data(data): #populates a list with parameter from checked checkbuttons,
global cb_var_init
cb_var_list = list(map(lambda var: var.get(),list(cb_var.values())))
for i in range(len(data)):
if cb_var_list[i] > cb_var_init[i]:
input_params.append(data[i])
elif cb_var_list[i] < cb_var_init[i]:
input_params.remove(data[i])
cb_var_init = cb_var_list
return(input_params)
cb_var is a dictionary of IntVars, and data is a list of checkbuttons' names.
As for the command on each checkbutton, I used cbname.config(text=data[i],command=lambda: get_data(data)) as suggested in another topic for functions with arguments.
Now each time I check a checkbutton, I immediately get a list of parameters which should show in the next Frame, which is dynamically updated.
I have a function, which based on the count generates the comboboxes. I want to destroy any combobox which is available already whenever my count variable changes. I used winfo_exists to do this...but it throws an attribute error every time. Please help me with this.
Here is the code of that function:
def create(event):
count = combo.current()
print ("count")
print(count)
for i in range(1,count+2):
if (create_combo[i].winfo_exists()):
create_combo[i].destroy()
for i in range (1,count+2):
create = tk.StringVar()
create_combo[i]= ttk.Combobox(new_window_2,width = 15,textvariable = create, values = sheets)
#create_combo.set("Sheet " + str(i))
create_combo[i].grid(column = i, row =4, padx=10,pady=10)
To delete the widgets which are created in loop, can be deleted by using the method available in this link
Python Tkinter :removing widgets that were created using a for loop
This worked for me... I dont understand why winfo_exists didn't work.
Anyway Thanks!!
list_of_owner_widgets = []
def create(event):
count = combo.current()
print(count)
for widget in list_of_owner_widgets:
widget.destroy()
for i in range (1,count+2):
create = tk.StringVar()
create_combo[i]= ttk.Combobox(new_window_2,width = 15,textvariable = create, values = sheets)
list_of_owner_widgets.append(create_combo[i])
create_combo[i].grid(column = i, row =4, padx=10,pady=10)
If you wish to destroy a Python widget, be it a Checkbox in your case, you use the following code.
It is a lot easier to remove and show widgets using the .grid method!
Your code:
create_combo[i].destroy()
I assume (as I can see further down the code file) that you used the grid method. In which case I would simply change the code to:
create_combo[i].grid_forget()
Hope This Helps!
From your post:
for i in range(1,count+2):
if (create_combo[i].winfo_exists()):
create_combo[i].destroy()
And the error:
AttributeError: 'str' object has no attribute 'winfo_exists'
I can infer that:Your create_combo must be a list full of string(Instead of Combobox widget).
You could add print(create_combo) before the first for loop to check the value in create_combo.It must be a list full of string.
And it seems that your problem is not here,you should check the way how you create the create_combo.
lets assume create_combo = ['a','b','c']. So I am creating three comboboxes create_combo[0...2]. So name of the comboboxes(widgets) is a, b, c.
No,you couldn't.
If really want to get a list of comboboxes you create,you should use:
create_combo = []
for i in range(3):
t = ttk.Combobox(xxxxx)
t.grid(xxxxxx)
create_combo.append(t) # append it to your create_combo
And then,you could use:
for i in create_combo:
if i.winfo_exists(): # i should be a widget,not string
xxxxxxx # your job
I have a table (grid) I'm creating, constituted of labels.
These labels are showing elements I'm adding to a list, therefore, when I add a new obj to the list, the table will grow, showing more labels.
My intent is that I can click a label and have it print the row of the table that that label is in.
import tkinter as tk
phrasesdb = []
def debug(event):
#this is where I'd have it print the row
#but how do I get it?
#for example, it the label I pressed was in the row 2, it'd print 2
print( ??? )
#Add obj to list
def addline():
##This creates new obj with values from the input fields, and inserts it in the list
newobj = {"text": newtext.get()} #This is getting the text from an Entery
phrasesdb.append(newobj)
##This shows new obj on the table
newesttext = tk.Label(tableframe, text=newobj["text"])
newesttext.grid(row=len(phrasesdb), column=1, sticky=tk.W)
newesttext.bind("<Double-Button-1>", debug)
I'm already able to show them in the table, and to have it recognize I'm pressing the correct label (tested with a simple print("yup, this is it") ), but I'm not being able to figure out how to access the row of the label I'm clicking.
I'm kinda new to python and especially tkinter, so sorry if this is a really easy question, but I'm not finding the answer anywhere else...
You can use the grid_info method which will return a dictionary of the item's grid attributes.
def debug(event):
widget = event.widget
info = widget.grid_info()
row = info['row']
If I understand your problem correctly using .grid_info()['row'] on the label you already received after clicking should return the result you need.
Is there an easier way to change the order of items in a tkinter listbox than deleting the values for specific key, then re-entering new info?
For example, I want to be able to re-arrange items in a listbox. If I want to swap the position of two, this is what I've done. It works, but I just want to see if there's a quicker way to do this.
def moveup(self,selection):
value1 = int(selection[0]) - 1 #value to be moved down one position
value2 = selection #value to be moved up one position
nameAbove = self.fileListSorted.get(value1) #name to be moved down
nameBelow = self.fileListSorted.get(value2) #name to be moved up
self.fileListSorted.delete(value1,value1)
self.fileListSorted.insert(value1,nameBelow)
self.fileListSorted.delete(value2,value2)
self.fileListSorted.insert(value2,nameAbove)
Is there an easier way to change the order of items in a tkinter listbox than deleting the values for specific key, then re-entering new info?
No. Deleting and re-inserting is the only way. If you just want to move a single item up by one you can do it with only one delete and insert, though.
def move_up(self, pos):
""" Moves the item at position pos up by one """
if pos == 0:
return
text = self.fileListSorted.get(pos)
self.fileListSorted.delete(pos)
self.fileListSorted.insert(pos-1, text)
To expand on Tim's answer, it is possible to do this for multiple items as well if you use the currentselection() function of the tkinter.listbox.
l = self.lstListBox
posList = l.curselection()
# exit if the list is empty
if not posList:
return
for pos in posList:
# skip if item is at the top
if pos == 0:
continue
text = l.get(pos)
l.delete(pos)
l.insert(pos-1, text)
This would move all selected items up 1 position. It could also be easily adapted to move the items down. You would have to check if the item was at the end of the list instead of the top, and then add 1 to the index instead of subtract. You would also want to reverse the list for the loop so that the changing indexes wouldn't mess up future moves in the set.
I have a method that is suppose to take a search parameter and remove everything from the list that does not meet the parameter. But when it runs it removes list items at almost random. I've debugged it and it correctly determines if an item needs to be removed but it doesn't remove the right one. I think it has something to do with when I remove one item it messes up the indexes of the rest of the list, which doesn't with with my method of tracking the index.
I posted the whole class but the relevant code is towards the bottom
class StudentFinderWindow(Tkinter.Toplevel):
def __init__(self):
Tkinter.Toplevel.__init__(self) # Create Window
##### window attributes
self.title('Edit Students') #sets window title
##### puts stuff into the window
# text
editStudentInfoLabel = Tkinter.Label(self,text='Select the student from the list below or search for one in the search box provided')
editStudentInfoLabel.grid(row=0, column=0)
# entry box
self.searchRepositoryEntry = Tkinter.Entry(self)
self.searchRepositoryEntry.grid(row=1, column=0)
# list box
self.searchResults = Tkinter.Listbox(self)
self.searchResults.grid(row=2, column=0)
# search results initial updater
self.getStudentList()
for student in self.studentList:
self.searchResults.insert(Tkinter.END, student)
##### event handler
self.searchRepositoryEntry.bind('<KeyRelease>', self.updateSearch)
This is the relevant code
def updateSearch(self, event):
parameters = self.searchRepositoryEntry.get()
int = 0
currentList = self.searchResults.get(0, Tkinter.END)
length = len(parameters)
print(parameters)
print(length)
for i in currentList:
if not i[0:length] == parameters:
self.searchResults.delete(int)
print(i[0:length] == parameters)
print(i[0:length])
print(int)
int += 1
def getStudentList(self):
global fileDirectory # gets the directory that all the files are in
fileList = listdir(fileDirectory) # makes a list of files from the directory
self.studentList = [] # makes a new list
for file in fileList: # for loop that adds each item from the file list to the student list
self.studentList.append(file[:-4])
When you delete an item, everything below it moves up causing the index of all following items to change. The simplest solution to this sort of a problem (it's also common when deleting words from a text widget) is to delete backwards, starting at the end.
I think you already know the problem. When you delete an item, the index for the rest of the items change. For example, if you delete the 4th item, then the 5th item becomes the "new" 4th item. So you don't want to increment int whenever you delete an item. You can implement that with continue:
for i in currentList:
if not i[0:length] == parameters:
self.searchResults.delete(int)
continue # <-- Use continue so `int` does not increment.
int += 1
PS. It's not good coding style to use int as a variable name -- in Python it masks the built-in function of the same name.