import requests
import os
from urllib.parse import urlencode
from hashlib import md5
from multiprocessing.pool import pool
from requests import codes
def get_page(offset):
  params = {
    "offset":offset,
    "format":"json",
    "keyword":"街拍",
    "autoload":"true",
    "count":"20",
    "cur_tab":"1",
    "from":"search_tab"
  }
  url = '#search_content/?'+urlencode(params)
  try:
    response = requests.get(url)
    if response.status_code == 200:
      # print(url)
      return response.json()
  except requests.connectionerror:
    return none
# get_page(0)
def get_images(json):
  if json.get('data'):
    for item in json.get('data'):
      if item.get('cell_type') is not none:
        continue
      title = item.get('title')
      images = item.get('image_list')
      for image in images:
        yield {
          'title':title,
          'image':'https:' + image.get('url'),
        }
def save_image(item):
  #os.path.sep  路径分隔符‘//'
  img_path = 'img' + os.path.sep + item.get('title')
  if not os.path.exists(img_path):
    os.makedirs(img_path)
  try:
    resp = requests.get(item.get('image'))
    # print(type(resp))
    if codes.ok == resp.status_code:
      file_path = img_path + os.path.sep + '{file_name}.{file_suffix}'.format(
        file_name=md5(resp.content).hexdigest(),#md5是一种加密算法获取图片的二进制数据，以二进制形式写入文件
        file_suffix='jpg')
      if not os.path.exists(file_path):
        with open(file_path,'wb')as f:
          f.write(resp.content)
          print('downladed image path is %s' % file_path)
      else:
        print('already downloaded',file_path)
  except requests.connectionerror:
    print('failed to save image,item %s' % item)
def main(offset):
  json = get_page(offset)
  for item in get_images(json):
    print(item)
    save_image(item)
group = 0
group_end = 2
if __name__ == '__main__':
  pool = pool()
  groups = ([x*20 for x in range(group,group_end)])
  pool.map(main,groups)  #将groups一个个调出来传给main函数
  pool.close()
  pool.join()   #保证子进程结束后再向下执行 pool.join(1) 等待一秒