How to change font size of child QLabel widget from the groupBox

Question

How can use different font & size for the child Widgets in the GroupBox and the tittle for the GroupBox in python

def panel(self):
    groupBox = QtGui.QGroupBox("voltage Monitor")
    groupBox.setFont(QtGui.QFont('SansSerif', 13))       # the title size is good
    ..

    self.Voltage_Label = []
    ..

    vbox = QtGui.QGridLayout()
    self.Voltage_Label.append(QtGui.QLabel("voltage1 ")) # i need to have diff Font & size for these 
    self.Voltage_Label.append(QtGui.QLabel("voltage2 "))   
    self.Voltage_Label.append(QtGui.QLabel("voltage3 ")) 
    ..
    vbox.addWidget(self.Voltage_Label[i], i, 0)  
    ..
    groupBox.setLayout(vbox)
    return groupBox

I tired this

   self.Voltage_Label.setFont(QtGui.QFont('SansSerif', 10))

I get this error

    !! self.Voltage_Label.setFont(QtGui.QFont('SansSerif', 10))
AttributeError: 'list' object has no attribute 'setFont' !!

but for something like thistitle1 = QtGui.QLabel("Sample Title") as a child widget i can change it by

 title1.setFont(QtGui.QFont('SansSerif', 10))

score 12 · Accepted Answer · edited Jan 03 '17 at 06:20

12

While I was waiting for an answer I wanted to give it a try and found this method/solution for my question:

self.Voltage_Label = []

self.Voltage_Label.append(QtGui.QLabel("voltage1 ")) # i need to have diff Font & size for these 
self.Voltage_Label.append(QtGui.QLabel("voltage2 "))   
self.Voltage_Label.append(QtGui.QLabel("voltage3 "))
.
.

for i in xrange(5):
        newfont = QtGui.QFont("Times", 8, QtGui.QFont.Bold) 
        self.Voltage_Label[i].setFont(newfont)

edited Jan 03 '17 at 06:20

Cheyn Shmuel

428
8
15

answered Sep 22 '15 at 19:09

user2345

537
1
5
22

this doesn't change the fonts while ui setup already rendered – greendino Oct 14 '20 at 08:24

Nuno André · Answer 2 · 2016-03-19T03:16:59.543

You were trying to invoke the method setFont() of an object of the class list (which hasn't this method), not of the QtGui.QLabel object.

You can use a list comprehension for a better scalability and performance:

voltages = ["voltage1 ", "voltage2 ", "voltage3 "]

# Populates the list with QLabel objects
self.Voltage_Label = [QtGui.QLabel(x) for x in voltages]

# Invokes setFont() for each object
[x.setFont(QtGui.QFont("Times", 8, QtGui.QFont.Bold)) for x in self.Voltage_Label]

If you need more voltage labels you only have to modify the list voltages.

And then even:

[vbox.addWidget(self.Voltage_Label[i], i, 0) for i in range(len(self.Voltage_Label))]

Hyperx837 · Answer 3 · 2020-06-09T08:11:44.050

2

also, you can try

font = QtGui.QFont("Times", 8, QtGui.QFont.Bold)
[label.setFont(font) for label in self.Voltage_Label]

if you are creating a font object every time you iterate over an item of self.Voltage_Label it will cost you some memory. so, therefore, you can share the same one with all the labels. whenever memory matters you can use this technique. but if you want to change the font on all label objects it won't change the font in other QLabel objects.

edited Jun 09 '20 at 08:11

answered Jun 09 '20 at 02:59

Hyperx837

773
5
13

1

While this code may answer the question, providing additional context regarding why and/or how this code answers the question improves its long-term value. – Nic3500 Jun 09 '20 at 04:56

How to change font size of child QLabel widget from the groupBox

3 Answers3