73 lines
1.6 KiB
Python
73 lines
1.6 KiB
Python
"""Download flags of top 20 countries by population
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asyncio + aiottp version
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Sample run::
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$ python3 flags_asyncio.py
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CN EG BR IN ID RU NG VN JP DE TR PK FR ET MX PH US IR CD BD
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20 flags downloaded in 0.35s
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"""
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# BEGIN FLAGS_ASYNCIO
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import os
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import time
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import sys
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import asyncio # <1>
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import aiohttp # <2>
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POP20_CC = ('CN IN US ID BR PK NG BD RU JP '
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'MX PH VN ET EG DE IR TR CD FR').split()
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BASE_URL = 'http://flupy.org/data/flags'
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DEST_DIR = 'downloads/'
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def save_flag(img, filename):
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path = os.path.join(DEST_DIR, filename)
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with open(path, 'wb') as fp:
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fp.write(img)
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async def get_flag(session, cc): # <3>
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url = '{}/{cc}/{cc}.gif'.format(BASE_URL, cc=cc.lower())
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async with session.get(url) as resp: # <4>
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return await resp.read() # <5>
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def show(text):
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print(text, end=' ')
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sys.stdout.flush()
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async def download_one(session, cc): # <6>
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image = await get_flag(session, cc) # <7>
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show(cc)
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save_flag(image, cc.lower() + '.gif')
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return cc
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async def download_many(cc_list):
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async with aiohttp.ClientSession() as session: # <8>
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res = await asyncio.gather( # <9>
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*[asyncio.create_task(download_one(session, cc))
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for cc in sorted(cc_list)])
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return len(res)
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def main(): # <10>
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t0 = time.time()
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count = asyncio.run(download_many(POP20_CC))
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elapsed = time.time() - t0
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msg = '\n{} flags downloaded in {:.2f}s'
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print(msg.format(count, elapsed))
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if __name__ == '__main__':
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main()
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# END FLAGS_ASYNCIO
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