Work with forms

Read and set form-control values with form semantics, and collect a form’s data the way a browser submit would, through field_value and the form helpers.

Read and set form-field values

field_value is the control’s value with form semantics: a textarea’s text, an option’s value, or the selected option value(s) of a select (a list for a multiple select). Assigning writes it back, and checked reads or sets a checkbox or radio (setting a radio to True clears the other same-name radios in the form):

form = turbohtml.parse(
    "<form><input name=email value=a@b.c>"
    "<select name=plan><option value=free>Free<option value=pro selected>Pro</select>"
    "<input name=terms type=checkbox value=yes></form>"
).find("form")
print(form.find("input", attrs={"name": "email"}).field_value)
print(form.find("select").field_value)
form.find("input", attrs={"name": "terms"}).checked = True

a@b.c
pro

Serialize a form to name/value pairs

form_data() returns the form’s successful controls as (name, value) pairs in document order, following the WHATWG submission rules: unnamed, disabled, button, and unchecked checkbox/radio controls are skipped, and a select contributes one pair per selected option. Pass the result straight to urllib.parse.urlencode():

from urllib.parse import urlencode

print(form.form_data())
print(urlencode(form.form_data()))

[('email', 'a@b.c'), ('plan', 'pro'), ('terms', 'yes')]
email=a%40b.c&plan=pro&terms=yes