PyQT5 - align left

[deanhystad]

What is the problem? I ran your code and everything lines up to the left.

If you want to compute the fixed width of your LineEdit you can do that using the font metrics

import PySide6.QtWidgets as QtWidgets
from PySide6.QtGui import QFontMetrics
from PySide6.QtGui import Qt

def fitToText(widget, text, padding=10):
        """Set width to fit text"""
        pixels = QFontMetrics(widget.font()).boundingRect(text).width() + padding
        widget.setFixedWidth(pixels)
        return pixels

class MyWindow(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()
        self.lp_label = QtWidgets.QLabel("Low-pass (Hz): ", self)
        self.lp_label.setAlignment(Qt.AlignLeft)

        self.lp_edit = QtWidgets.QLineEdit("10", self)
        self.lp_edit.setAlignment(Qt.AlignLeft)
        fixed_width = fitToText(self.lp_edit, "000.00")

        self.hp_label = QtWidgets.QLabel("High-pass (Hz): ", self)
        self.hp_label.setAlignment(Qt.AlignLeft)

        self.hp_edit = QtWidgets.QLineEdit("10", self)
        self.hp_edit.setAlignment(Qt.AlignLeft)
        self.hp_edit.setFixedWidth(fixed_width)


        self.hanning_sel = QtWidgets.QComboBox(self)
        self.hanning_sel.addItems(["Hanning", "Hamming", "Flat", "None"])
        fitToText(self.hanning_sel, "Hamming", 30)


        buttonbox3 = QtWidgets.QVBoxLayout(self)
        buttonbox3.addWidget(self.lp_label)
        buttonbox3.addWidget(self.lp_edit)
        buttonbox3.addWidget(self.hp_label)
        buttonbox3.addWidget(self.hp_edit)
        buttonbox3.addWidget(self.hanning_sel)

app = QtWidgets.QApplication()
window = MyWindow()
window.show()
app.exec()

Please provide a runnable example next time you post