Python Generator返回最后一个项目

Question

I'm trying to loop through a CSV file and get an item from each row and insert it into the QLineEdit in the GUI.

When I click the button self.nextAppointment it fills the field in, but always with the very last row's email address in the CSV file. Subsequent clicks of the button do not appear to do anything.

I'm thinking that I'm not creating/using the generator correctly, but I am not sure.

How do I loop over the CSV file and get the fields I want returned so I can put that into the GUI on at a time for each row of the CSV.

Here is the relevant code:

self.nextAppointment.clicked.connect(self.nextFunction)

def nextFunction(self):
    self.emailGenerator = self.nextEmail()
    for email in self.emailGenerator:
        self.toField.setText(email)


def nextEmail(self):
    with open('assigned_appt_leads.csv', 'rb') as infile:
        rdr = csv.DictReader(infile, dialect='excel')
        for line in rdr:
            yield line['Email Address']

I've tested using the following and it gets the first email address, but pressing next does not change it to the next row's email address.

def nextFunction(self):
    self.emailGenerator = self.nextEmail()
    self.toField.setText(self.emailGenerator.next())

Answer 1

You are correctly looping and yielding.

What you are not doing is use the results correctly:

for email in self.emailGenerator:
    self.toField.setText(email)

will replace any previous textual value each loop iteration . This is why you see the last value only; all previous calls to self.toField.setText() succeeded, but where then overwritten again by the next iteration.

You need to append to the existing text in the QLineEdit widget instead. I suggest you use the .insert() method:

for email in self.emailGenerator:
    self.toField.insert(email + '\n')

If you wanted to assign items one by one to your field on user events, call next() on self.emailGenerator every time you need a new address:

self.toField.insert(next(self.emailGenerator, ''))

instead of looping over it. The above sample line sets the field to '' if you've run out of email addresses.