from PIL import Image
import os

def get_size(file):
  # 获取文件大小:KB
  size = os.path.getsize(file)
  return size / 1024

def get_outfile(infile, outfile):
  if outfile:
    return outfile
  dir, suffix = os.path.splitext(infile)
  outfile = '{}-out{}'.format(dir, suffix)
  return outfile

def compress_image(infile, outfile='', mb=150, step=10, quality=80):
  """不改变图片尺寸压缩到指定大小
  :param infile: 压缩源文件
  :param outfile: 压缩文件保存地址
  :param mb: 压缩目标，KB
  :param step: 每次调整的压缩比率
  :param quality: 初始压缩比率
  :return: 压缩文件地址，压缩文件大小
  """
  o_size = get_size(infile)
  if o_size <= mb:
    return infile
  outfile = get_outfile(infile, outfile)
  while o_size > mb:
    im = Image.open(infile)
    im.save(outfile, quality=quality)
    if quality - step < 0:
      break
    quality -= step
    o_size = get_size(outfile)
  return outfile, get_size(outfile)

def resize_image(infile, outfile='', x_s=1376):
  """修改图片尺寸
  :param infile: 图片源文件
  :param outfile: 重设尺寸文件保存地址
  :param x_s: 设置的宽度
  :return:
  """
  im = Image.open(infile)
  x, y = im.size
  y_s = int(y * x_s / x)
  out = im.resize((x_s, y_s), Image.ANTIALIAS)
  outfile = get_outfile(infile, outfile)
  out.save(outfile)
if __name__ == '__main__':
  compress_image(r'D:\learn\space.jpg')
  resize_image(r'D:\learn\space.jpg')