一、Python-Flask-文件上传

1、简化版文件上传

创建目录：

cd 5-4

mkdir -p uploads #必须先创建uploads文件夹。

upload.html

Title

文件上传示例

app.py

import os

from flask import Flask, render_template, send_from_directory, request, jsonify, make_response

import time

app = Flask(__name__)

UPLOAD_FOLDER = 'upload'

app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER # 设置文件上传的目标文件夹

basedir = os.path.abspath(os.path.dirname(__file__)) # 获取当前项目的绝对路径

ALLOWED_EXTENSIONS = set(['txt', 'png', 'jpg', 'xls', 'JPG', 'PNG', 'xlsx', 'gif', 'GIF']) # 允许上传的文件后缀

# 判断文件是否合法

def allowed_file(filename):

return '.' in filename and filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS

# 具有上传功能的页面

@app.route('/')

def upload_test():

return render_template('upload.html')

@app.route('/api/upload', methods=['POST'], strict_slashes=False)

def api_upload():

file_dir = os.path.join(basedir, app.config['UPLOAD_FOLDER']) # 拼接成合法文件夹地址

if not os.path.exists(file_dir):

os.makedirs(file_dir) # 文件夹不存在就创建

f = request.files['myfile'] # 从表单的file字段获取文件，myfile为该表单的name值

if f and allowed_file(f.filename): # 判断是否是允许上传的文件类型

fname = f.filename

ext = fname.rsplit('.', 1)[1] # 获取文件后缀

unix_time = int(time.time())

new_filename = str(unix_time) + '.' + ext # 修改文件名

f.save(os.path.join(file_dir, new_filename)) # 保存文件到upload目录

return jsonify({"errno": 0, "errmsg": "上传成功"})

else:

return jsonify({"errno": 1001, "errmsg": "上传失败"})

# file download

@app.route("/download/")

def downloader(filename):

dirpath = os.path.join(app.root_path, 'upload') # 这里是下在目录，从工程的根目录写起，比如你要下载static/js里面的js文件，这里就要写“static/js”

# return send_from_directory(dirpath, filename, as_attachment=False) # as_attachment=True 一定要写，不然会变成打开，而不是下载

return send_from_directory(dirpath, filename, as_attachment=True) # as_attachment=True 下载

# show photo

@app.route('/show/', methods=['GET'])

def show_photo(filename):

file_dir = os.path.join(basedir, app.config['UPLOAD_FOLDER'])

if request.method == 'GET':

if filename is None:

pass

else:

image_data = open(os.path.join(file_dir, '%s' % filename), "rb").read()

response = make_response(image_data)

response.headers['Content-Type'] = 'image/png'

return response

else:

pass

if __name__ == '__main__':

app.run(debug=True)

访问网站：

2、优化版文件上传

2.1. 自动创建upload文件夹。

upload.html

Title

上传文件

app.py

import os

from flask import Flask, render_template, send_from_directory, request, jsonify

import time

app = Flask(__name__)

UPLOAD_FOLDER = 'upload'

app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER # 设置文件上传的目标文件夹

basedir = os.path.abspath(os.path.dirname(__file__)) # 获取当前项目的绝对路径

ALLOWED_EXTENSIONS = set(['txt', 'png', 'jpg', 'xls', 'JPG', 'PNG', 'xlsx', 'gif', 'GIF']) # 允许上传的文件后缀

# 判断文件是否合法

def allowed_file(filename):

return '.' in filename and filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS

# 具有上传功能的页面

@app.route('/')

def upload_test():

return render_template('upload.html')

@app.route('/api/upload', methods=['POST'], strict_slashes=False)

def api_upload():

file_dir = os.path.join(basedir, app.config['UPLOAD_FOLDER']) # 拼接成合法文件夹地址

if not os.path.exists(file_dir):

os.makedirs(file_dir) # 文件夹不存在就创建

f = request.files['myfile'] # 从表单的file字段获取文件，myfile为该表单的name值

if f and allowed_file(f.filename): # 判断是否是允许上传的文件类型

fname = f.filename

ext = fname.rsplit('.', 1)[1] # 获取文件后缀

unix_time = int(time.time())

new_filename = str(unix_time) + '.' + ext # 修改文件名

f.save(os.path.join(file_dir, new_filename)) # 保存文件到upload目录

return jsonify({"errno": 0, "errmsg": "上传成功"})

else:

return jsonify({"errno": 1001, "errmsg": "上传失败"})

# file download

@app.route("/download/")

def downloader(filename):

dirpath = os.path.join(app.root_path, 'upload') # 这里是下在目录，从工程的根目录写起，比如你要下载static/js里面的js文件，这里就要写“static/js”

# return send_from_directory(dirpath, filename, as_attachment=False) # as_attachment=True 一定要写，不然会变成打开，而不是下载

return send_from_directory(dirpath, filename, as_attachment=True) # as_attachment=True 下载

if __name__ == '__main__':

app.run(debug=True)访

1.2.访问网址

上传成功，返回值

下载文件

http://127.0.0.1:5000/download/1597310075.png

查看图片