Do you create your examples with a designer?
I think using
setGeometry for all widgets is not a good idea.
Shrinking the window has the effect that your widgets are no longer visible.
I changed your ProgressBar Example this way
from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow
import sys
def update():
reset()
completed = 0
while completed < 100:
completed += 0.0001
prog_bar.setValue(completed)
def reset():
value = 0
prog_bar.setValue(value)
app = QApplication(sys.argv)
win = QMainWindow()
win.setGeometry(400,400,300,150)
win.setWindowTitle("CodersLegacy")
prog_bar = QtWidgets.QProgressBar()
prog_bar.setFixedHeight(26)
prog_bar.setValue(0)
button = QtWidgets.QPushButton(win)
button.setText("Update")
button.setFixedWidth(80)
button.clicked.connect(update)
reset_button = QtWidgets.QPushButton()
reset_button.setText("Reset")
reset_button.setFixedWidth(80)
reset_button.clicked.connect(reset)
prog_barwid = QtWidgets.QVBoxLayout()
prog_barwid.addWidget(prog_bar)
btn_wid = QtWidgets.QHBoxLayout()
btn_wid.addWidget(button)
btn_wid.addWidget(reset_button)
layout = QtWidgets.QVBoxLayout()
layout.addLayout(prog_barwid)
layout.addLayout(btn_wid)
main_wid = QtWidgets.QWidget()
main_wid.setLayout(layout)
main_wid.setFixedWidth(280)
main_wid.setFixedHeight(100)
win.setCentralWidget(main_wid)
win.show()
sys.exit(app.exec_())