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
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<h1>文件上传示例</h1>
<form action="" enctype='multipart/form-data' method='POST'>
<input type="file" name="file">
<input type="submit" value="上传">
</form>
</body>
</html>
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/<path:filename>")
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/<string:filename>', 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
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<h1>上传文件</h1>
<body>
<form id="form1" method="post" action="/api/upload" enctype="multipart/form-data">
<div>
<input id="File1" type="file" name="myfile"/> <!--后台代码中获取文件是通过form的name来标识的-->
<input type="submit">提交</input>
</div>
</form>
</body>
</html>
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/<path:filename>")
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
http://127.0.0.1:5000/show/1597309506.png
