python 导入导出文件

1、最简单的文件下载功能

def file_download(request):
    with open('file_name.txt') as f:
        c = f.read()
    return HttpResponse(c)

2、更合理的文件下载功能

from django.http import StreamingHttpResponse

def big_file_download(request):
    def file_iterator(file_name,chunk_size=512):
        with open(file_name) as f:
            while True:
                c = f.read(chunk_size)
                if c:
                    yield c
                else:
                    break
    the_file_name = "file_name.txt"
    response = StreamingHttpResponse(file_iterator(the_file_name))
    return response

3、文件下载功能再次优化

from django.http import StreamingHttpResponse
def big_file_download(request):
    # do something... 
    def file_iterator(file_name, chunk_size=512):
    with open(file_name) as f:
        while True:
        c = f.read(chunk_size)
        if c:
            yield c
        else:
            break

    the_file_name = "big_file.pdf"
    response = StreamingHttpResponse(file_iterator(the_file_name))
    response['Content-Type'] = 'application/octet-stream'
    response['Content-Disposition'] = 'attachment;filename="{0}"'.format(the_file_name) 
    return response

4、直接导出Excel表格

import xlwt
import io
import json
from django.http import HttpResponse
def set_style(name, height, bold=False):
  style = xlwt.XFStyle() # 初始化样式
  font = xlwt.Font() # 为样式创建字体
  font.name = name # 'Times New Roman'
  font.bold = bold
  font.color_index = 000
  font.height = height
  style.font = font
  # 设置单元格边框
  # borders= xlwt.Borders()
  # borders.left= 6
  # borders.right= 6
  # borders.top= 6
  # borders.bottom= 6
  # style.borders = borders
 
  # 设置单元格背景颜色
  # pattern = xlwt.Pattern()
  # 设置其模式为实型
  # pattern.pattern = pattern.SOLID_PATTERN
  # 设置单元格背景颜色
  # pattern.pattern_fore_colour = 0x00
  # style.pattern = pattern
 
  return style
 
def write_excel(data, name, header):
    # 打开一个Excel工作簿
    file = xlwt.Workbook()
    # 新建一个sheet，如果对一个单元格重复操作，会引发异常，所以加上参数cell_overwrite_ok=True
    table = file.add_sheet(name, cell_overwrite_ok=True)
    if data is None:
    return file
    # 写标题栏
    row0 = [u'业务', u'状态', u'北京', u'上海', u'广州', u'深圳', u'状态小计']
    for i in range(0, len(row0)):
    table.write_merge(0, 0, i, i, row0[i], set_style('Times New Roman', 220, True))
    table.write_merge(0, 2, 7, 9, "单元格合并", set_style('Times New Roman', 220, True))
    """
    table.write_merge(x, x + m, y, w + n, string, sytle)
    x表示行，y表示列，m表示跨行个数，n表示跨列个数，string表示要写入的单元格内容，style表示单元格样式。其中，x，y，w，h，都是以0开始计算的。
    """
    l = 0
    n = len(header)
    # 写入数据
    for line in data:
    for i in range(n):
        table.write(l, i, line[header[i]])
    l += 1
    # 直接保存文件
    # file.save("D:/excel_name.xls")
    # 写入IO
    res = get_excel_stream(file)
    # 设置HttpResponse的类型
    response = HttpResponse(content_type='application/vnd.ms-excel')
    from urllib import parse
    response['Content-Disposition'] = 'attachment;filename=' + parse.quote("excel_name") + '.xls'
    # 将文件流写入到response返回
    response.write(res)
    return response

    def get_excel_stream(file):
    # StringIO操作的只能是str，如果要操作二进制数据，就需要使用BytesIO。
    excel_stream = io.BytesIO()
    # 这点很重要，传给save函数的不是保存文件名，而是一个BytesIO流（在内存中读写）
    file.save(excel_stream)
    # getvalue方法用于获得写入后的byte将结果返回给re
    res = excel_stream.getvalue()
    excel_stream.close()
    return res

5、导出json格式

def write_json(data):
    try:
        json_stream = get_json_stream(data)
        response = HttpResponse(content_type='application/json')
        from urllib import parse
        response['Content-Disposition'] = 'attachment;filename=' + parse.quote("test") + '.json'
        response.write(json_stream)
        return response
    except Exception as e:
        print(e)
 
 
def get_json_stream(data):
    # 开始这里我用ByteIO流总是出错，但是后来参考廖雪峰网站用StringIO就没问题
    file = io.StringIO()
    data = json.dumps(data)
    file.write(data)
    res = file.getvalue()
    file.close()
    return res
6、导出压缩包
def write_zip(e_data, j_data, export_name):
    try:
        # 保存到本地文件
        # 返回文件名，注意此时保存的方法和前面导出保存的json、excel文件区别
        j_name = write_json(j_data, export_name[1])
        e_name = write_excel(e_data, export_name[1])
        # 本地文件写入zip，重命名，然后删除本地临时文件
        z_name='export.zip'
        z_file = zipfile.ZipFile(z_name, 'w')
        z_file.write(j_name)
        z_file.write(e_name)
        os.remove(j_name)
        os.remove(e_name)
        z_file.close()
        # 再次读取zip文件，将文件流返回,但是此时打开方式要以二进制方式打开
        z_file = open(z_name, 'rb')
        data = z_file.read()
        z_file.close()
        os.remove(z_file.name)
        response = HttpResponse(data, content_type='application/zip')
        from urllib import parse
        response['Content-Disposition'] = 'attachment;filename=' + parse.quote(z_name)
        return response
    except Exception as e:
        logging.error(e)
        print(e)

连接数据库导出表格

import xlwt
import xlrd
import pymysql


conn = pymysql.connect(
    host = '10.0.122.120',
    port = 3306,
    user = 'king',
    passwd = 'QFedu123!'
)

cursor = conn.cursor()

cursor.execute("use dj21gp01")
cursor.execute("select * from server")
col = cursor.description

data = cursor.fetchall()


wb = xlwt.Workbook()

ws = wb.add_sheet("dj21gp01",cell_overwrite_ok=True)

for i in range(len(col)):
    ws.write(0,i,col[i][0])


row = 1
for item in data:
    for j in range(len(item)):
        ws.write(row,j,item[j])
    row += 1

wb.save("/root/桌面/server_info.xls")

cursor.close()