CSV reader with PyQt6

[suburbanprojects]

A basic CSV reader with save function made with pyqt6. Code also available at the following github page.

import sys
import pandas as pd
from pathlib import Path
from PyQt6.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout, QLineEdit, 
                             QPushButton, QHBoxLayout, QTableWidget, 
                             QTableWidgetItem, QFileDialog)

class csvViewer(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle('CSV Viewer')
        #set widgets
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        #set text field
        self.layout = QVBoxLayout(self.central_widget)
        self.open_file = QLineEdit(self)
        self.layout.addWidget(self.open_file)
        #add the buttons
        button_layout = QHBoxLayout()

        self.open_button = QPushButton('Open File', self)
        button_layout.addWidget(self.open_button)
        self.open_button.clicked.connect(self.open_dialog_1)
        self.save_button = QPushButton('Save File',self)
        button_layout.addWidget(self.save_button)
        self.save_button.clicked.connect(self.save_csv)

        self.layout.addLayout(button_layout)

        #add table
        self.table_entry = QTableWidget(self)
        self.layout.addWidget(self.table_entry)

    def open_dialog_1(self):
        #open file to select csv file
        fname, ok = QFileDialog.getOpenFileName(
            self,
            "Open File",
            "${HOME}",
            "CSV Files (*.csv)",
        ) 
        if fname:
            path = Path(fname)
            self.open_file.setText(str(path))
            #read csv file into pandas dataframe (df)
            df = pd.read_csv(fname)
            #set table dimensions
            self.table_entry.setRowCount(df.shape[0]) #set rows
            self.table_entry.setColumnCount(df.shape[1]) #set columns
            self.table_entry.setHorizontalHeaderLabels(df.columns) #set column headers
            
            # Populate table with CSV data
            for row_idx in range(df.shape[0]):
                for col_idx in range(df.shape[1]):
                    cell_value = str(df.iloc[row_idx, col_idx]) #convert value to string
                    self.table_entry.setItem(row_idx, col_idx, QTableWidgetItem(cell_value))


    def save_csv(self):
        # Open file dialog to save CSV
        fname, ok = QFileDialog.getSaveFileName(self, "Save CSV File", "", "CSV Files (*.csv)")

        if fname:
            # Extract data from table
            row_count = self.table_entry.rowCount()
            col_count = self.table_entry.columnCount()
            headers = [self.table_entry.horizontalHeaderItem(i).text() for i in range(col_count)]

            data = []
            for row in range(row_count):
                row_data = []
                for col in range(col_count):
                    item = self.table_entry.item(row, col)
                    row_data.append(item.text() if item else "")
                data.append(row_data)

            # Create a DataFrame and save it as CSV
            df = pd.DataFrame(data, columns=headers)
            df.to_csv(fname, index=False)

if __name__=='__main__':
    app = QApplication(sys.argv)
    main_window = csvViewer()
    main_window.show()
    sys.exit(app.exec())

[Axel_Erfurt]

        fname, ok = QFileDialog.getOpenFileName(
            self,
            "Open File",
            "${HOME}",
            "CSV Files (*.csv)",
        ) 

${HOME} , this cannot work to open home folder

try

from PyQt6.QtCore import QDir

        homefolder =  QDir.homePath()
        fname, ok = QFileDialog.getOpenFileName(
            self,
            "Open File",
            homefolder,
            "CSV Files (*.csv)",
        ) 

[suburbanprojects]

I didn't know you can also do it that way, will give it a try.

[Axel_Erfurt]

Using a toolbar for the buttons looks better...

import sys
import pandas as pd
from pathlib import Path
from PyQt6.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout, 
                             QPushButton, QTableWidget, QLabel, 
                             QTableWidgetItem, QFileDialog, QStyle)
from PyQt6.QtCore import QDir
 
class CSV_Viewer(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()
 
    def initUI(self):
        self.setWindowTitle('CSV Viewer')
        #set widgets
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        self.layout = QVBoxLayout(self.central_widget)

        
        #add the buttons in a toolbar
        tb = self.addToolBar("File")
        tb.setStyleSheet("QPushButton{margin: 5px 5px; height: 24px;}")
        self.open_button = QPushButton('Open')
        self.open_button.setIcon(self.style().standardIcon(QStyle.StandardPixmap.SP_DialogOpenButton))
        tb.addWidget(self.open_button)
        self.open_button.clicked.connect(self.open_dialog_1)
        self.save_button = QPushButton('Save')
        self.save_button.setIcon(self.style().standardIcon(QStyle.StandardPixmap.SP_DialogSaveButton))
        tb.addWidget(self.save_button)
        self.save_button.clicked.connect(self.save_csv)
 
        #set text field
        self.open_file = QLabel()
        tb.addWidget(self.open_file)
 
        #add table
        self.table_entry = QTableWidget()
        self.layout.addWidget(self.table_entry)
        
        self.setGeometry(50, 50, 800, 600)
 
    def open_dialog_1(self):
        #open file to select csv file
        homefolder =  QDir.homePath()
        fname, ok = QFileDialog.getOpenFileName(
            self,
            "Open File",
            homefolder,
            "CSV Files (*.csv)"
        ) 
        if fname:
            path = Path(fname)
            self.open_file.setText(str(path))
            #read csv file into pandas dataframe (df)
            # sep="\t" for tab delimited 
            # na_filter=False to replace nan with empty string
            df = pd.read_csv(fname, na_filter=False)
            #set table dimensions
            self.table_entry.setRowCount(df.shape[0]) #set rows
            self.table_entry.setColumnCount(df.shape[1]) #set columns
            self.table_entry.setHorizontalHeaderLabels(df.columns) #set column headers
             
            # Populate table with CSV data
            for row_idx in range(df.shape[0]):
                for col_idx in range(df.shape[1]):
                    cell_value = str(df.iloc[row_idx, col_idx]) #convert value to string
                    self.table_entry.setItem(row_idx, col_idx, QTableWidgetItem(cell_value))
 
 
    def save_csv(self):
        # Open file dialog to save CSV
        homefolder =  QDir.homePath()
        fname, ok = QFileDialog.getSaveFileName(self, "Save CSV File", f"{homefolder}/*.csv", "CSV Files (*.csv)")
 
        if fname:
            # Extract data from table
            row_count = self.table_entry.rowCount()
            col_count = self.table_entry.columnCount()
            headers = [self.table_entry.horizontalHeaderItem(i).text() for i in range(col_count)]
 
            data = []
            for row in range(row_count):
                row_data = []
                for col in range(col_count):
                    item = self.table_entry.item(row, col)
                    row_data.append(item.text() if item else "")
                data.append(row_data)
 
            # Create a DataFrame and save it as CSV
            df = pd.DataFrame(data, columns=headers)
            df.to_csv(fname, index=False)
 
if __name__=='__main__':
    app = QApplication(sys.argv)
    main_window = CSV_Viewer()
    main_window.show()
    sys.exit(app.exec())