Python的Flask框架中实现登录用户的个人资料和头像的教程

以下是Python Flask框架实现用户个人资料和头像的教程攻略，分为两部分：

1. 用户个人资料的实现

1.1 创建用户资料模型

首先，我们需要在数据库中创建一个用户资料模型(model)，用来存储用户个人信息。模型主要包括以下几个字段：用户名、电子邮箱、密码、性别、生日等等。具体实现可参考以下代码：

from flask_login import UserMixin
from datetime import datetime
from your_app_name import db, login_manager

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    password = db.Column(db.String(60), nullable=False)
    gender = db.Column(db.String(6))
    birthday = db.Column(db.DateTime, default=datetime.utcnow)
    avatar = db.Column(db.String(20), nullable=False, default='default.jpg')

1.2 创建用户资料表单

接下来，我们需要为用户资料创建一个表单，这个表单主要包含用户资料的各项数据。用户可以通过这个表单进行修改和更新个人资料。具体实现可参考以下代码：

from flask_wtf import FlaskForm
from flask_wtf.file import FileField, FileAllowed
from wtforms import StringField, PasswordField, BooleanField, SubmitField, SelectField, DateField, TextAreaField
from wtforms.validators import DataRequired, Length, Email, EqualTo, ValidationError
from flask_login import current_user
from your_app_name.models import User

class UpdateAccountForm(FlaskForm):
    username = StringField('Username', validators=[DataRequired(), Length(min=2, max=20)])
    email = StringField('Email', validators=[DataRequired(), Email()])
    gender = SelectField('Gender', choices=[('Male', 'Male'), ('Female', 'Female')])
    birthday = DateField('Birthday')
    picture = FileField('Update Profile Picture', validators=[FileAllowed(['jpg', 'png'])])
    submit = SubmitField('Update')

    def validate_username(self, username):
        if username.data != current_user.username:
            user = User.query.filter_by(username=username.data).first()
            if user:
                raise ValidationError('That username is taken. Please choose a different one.')

    def validate_email(self, email):
        if email.data != current_user.email:
            user = User.query.filter_by(email=email.data).first()
            if user:
                raise ValidationError('That email is taken. Please choose a different one.')

1.3 创建用户资料视图

最后，我们需要为用户资料创建一个视图(view)，让用户能够在网页上查看和修改自己的个人信息。具体实现可参考以下代码：

from flask import render_template, url_for, flash, redirect, request
from flask_login import login_required, current_user
from your_app_name import app, db, bcrypt
from your_app_name.forms import UpdateAccountForm
from your_app_name.models import User

@app.route('/account', methods=['GET', 'POST'])
@login_required
def account():
    form = UpdateAccountForm()
    if form.validate_on_submit():
        if form.picture.data:
            picture_file = save_picture(form.picture.data)
            current_user.avatar = picture_file
        current_user.username = form.username.data
        current_user.email = form.email.data
        current_user.gender = form.gender.data
        current_user.birthday = form.birthday.data
        db.session.commit()
        flash('Your account has been updated!', 'success')
        return redirect(url_for('account'))
    elif request.method == 'GET':
        form.username.data = current_user.username
        form.email.data = current_user.email
        form.gender.data = current_user.gender
        form.birthday.data = current_user.birthday
    image_file = url_for('static', filename='profile_pics/' + current_user.avatar)
    return render_template('account.html', title='Account',
                           image_file=image_file, form=form)

1. 用户头像的实现

2.1 保存用户头像

用户头像（avatar）一般是以图片的形式呈现，因此我们需要一个保存用户头像的功能，以保证用户更新或上传头像后，程序能够正常保存并显示最新的头像。

import os
import secrets
from PIL import Image
from flask import current_app

def save_picture(form_picture):
    random_hex = secrets.token_hex(8)
    _, f_ext = os.path.splitext(form_picture.filename)
    picture_filename = random_hex + f_ext
    picture_path = os.path.join(current_app.root_path, 'static/profile_pics', picture_filename)

    output_size = (125, 125)
    i = Image.open(form_picture)
    i.thumbnail(output_size)

    i.save(picture_path)

    return picture_filename

2.2 修改用户资料表单

用户头像的上传和更新是通过表单实现的，因此我们需要在UpdateAccountForm中添加picture字段：

class UpdateAccountForm(FlaskForm):
    # ...
    picture = FileField('Update Profile Picture', validators=[FileAllowed(['jpg', 'png'])])
    submit = SubmitField('Update')

2.3 修改用户资料视图

最后，在account视图中添加保存用户头像的逻辑和显示头像的代码：

from your_app_name.utils import save_picture

# ...

@app.route('/account', methods=['GET', 'POST'])
@login_required
def account():
    form = UpdateAccountForm()
    if form.validate_on_submit():
        if form.picture.data:
            picture_file = save_picture(form.picture.data)
            current_user.avatar = picture_file
        # ...
    image_file = url_for('static', filename='profile_pics/' + current_user.avatar)
    return render_template('account.html', title='Account',
                           image_file=image_file, form=form)

至此，Python Flask框架实现用户个人资料和头像的教程攻略就结束了。