python-小知识点总结

浮点数保留位数

from decimal import Decimal
a = Decimal(5.333333333333).quantize(Decimal("0.00"))
print(a)

图片拼接

from PIL import Image
 
def join(png1, png2, flag='horizontal'):
  """
  :param png1: path
  :param png2: path
  :param flag: horizontal or vertical
  :return:
  """
  img1, img2 = Image.open(png1), Image.open(png2)
  size1, size2 = img1.size, img2.size
  if flag == 'horizontal':
    joint = Image.new('RGB', (size1[0]+size2[0], size1[1]))
    loc1, loc2 = (0, 0), (size1[0], 0)
    joint.paste(img1, loc1)
    joint.paste(img2, loc2)
    joint.save('horizontal.png')
  elif flag == 'vertical':
    joint = Image.new('RGB', (size1[0], size1[1]+size2[1]))
    loc1, loc2 = (0, 0), (0, size1[1])
    joint.paste(img1, loc1)
    joint.paste(img2, loc2)
    joint.save('vertical.png')
if __name__ == '__main__':
  png = 'lena.png'
  join(png, png)
  join(png, png, flag='vertical')

原文链接： https://www.zhangshengrong.com/p/7B1Lq6pPaw/

【导出】功能总结

import openpyxl
from utils.excel_utils import ExcelUtils
from openpyxl.writer.excel import save_virtual_workbook
from django.http import JsonResponse, HttpResponse

def cvt_pool_history_export(ls_obj):
    wb = openpyxl.Workbook()
    ws = wb.active
    ws.append(["调整日期", "简称"])
    for dic in ls_obj:
        ws.append((
            dic.get("created_time"),
            dic.get("simple_name"),
        ))
    ExcelUtils.format_excel(ws)
    ExcelUtils.simple_fmt_wh(ws)
    return save_virtual_workbook(wb)

def list(self, request, *args, **kwargs):
    queryset = self.filter_queryset(self.get_queryset())
    serializer = self.get_serializer(queryset, many=True)
    buffer = cvt_pool_history_export(serializer.data)
    response = HttpResponse(
        buffer, content_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    )
    response["Content-Disposition"] = "attachment; filename=XX导出.xlsx"
    return response