Flask form validation technique
Looking at register(), the format is as following:

def register():
    if request.method == "POST":
        if request.form['register'] == 'Register':
            stuff()
    return render_template("register.html",pageType=['register'])


This can easily be condensed using and:

def register():
    if request.method == "POST" and request.form['register'] == 'Register':
            stuff()
    return render_template("register.html", pageType=['register'])


Also, you are not inserting whitespaces between arguments.

stuff(3,3)  # &lt;--Unconventional
stuff(3, 3) # &lt;--More conventional


Another stylistic issue is some of your lines are too long. For all lines, line.length &lt;= 79. You can read about the specific python conventions on the Python website.
For making it look less messy and repetitive, look at this answer to a Stack Overflow question. It is about implementing switch and case statements into Python, which seems perfect for your situation.