Is there a function like trim() in python?
i use Flask miniframework and it doesn't accept:
selected_student = (request.args.get('student_form')).strip()
its error: AttributeError: 'NoneType' object has no attribute 'strip'
selected_student.replace(" ", "")
its error: AttributeError: 'NoneType' object has no attribute 'replace'
i need a function like trim() without coding a class/subclass or javascript
You're seeing the errors that you are seeing because there is no data being passed from your form to the Flask server. Your use of request is returning a None value type as opposed to a str.
You posted the following HTML mark up for your form:
<form action="/student" method='POST'>
<select name="student_form ">
{% for student in students_list %}
<option value="{{student}}">{{student}}</option>
{% endfor %}
</select>
<input type='submit' value='submit' />
</form>
So therefore you're going to need somewhere for Flask to pick up this data on the server side, for example:
@app.route('/student', methods=['POST'])
def receive_student_form_data:
my_selection = str(request.form.get('student_form')).strip()
print(my_selection)
Just to clarify why I've made my method in this way: I notice that you're using request.args.get() in order to retrieve the value sent by the form. This is incorrect.
request.args is used to retrieve key / value pairs from the URL.
request.form is used to retrieve key / value pairs from a HTML form.
So I'd suggest that you should use request.form.get('student_form') instead. If you really want to be certain that it is being cast as a str when retrieved by your Flask server, then you can cast it as a str as follows:
str(request.form.get('student_form'))
Then, as has been suggested by a few people already, you can use the .strip() method to remove any trailing spaces.
There is a strip() method. The error you get is because you are trying to run it on a NoneType object. You need to run it on a string object.
>>> s = 'some string '
>>> s.strip()
'some string'
There is also replace for strings:
>>> s.replace('some', 'many')
'many string '
The issue you encounter is related to something else. You end with a None object instead of what you are trying to get.
selected_student = (request.args.get('student_form')) and then try to print selected_student to get a print what the object is.content_selected = 'Printing file is failed'.strip(); but it doesn't work... and i tried print selected_student it doesn't print....; at the end of the statement in python
request.args.get('student_form')returnedNone, not a string, because the fieldstudent_formis not there. You could return a default''instead withrequest.args.get('student_form', '')but you probably should check why the field is not there in the first place.<form action="student" method='POST'> <select name="student_form "> {% for student in students_list %} <option value="{{student}}">{{student}}</option> {% endfor %} </select> <input type='submit' value='submit'> </form>and here is .py:... with app.open_resource('static/docs/student3.txt') as f3: content3 = f3.read()...and:... elif (selected_student == students_list[3]): content_selected = content3 ...i delete smthing, i think its clear. and i'm not sure is there any blank character in form data...form action="student". Youractionshould be a URL and should read as/student. I assume you've set up your Flask server to include the route/student, then, too?