mycode.py

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# -------------------------------------------------------------------
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# Import libraries
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# -------------------------------------------------------------------
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import math
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​
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# -------------------------------------------------------------------
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# Constants
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# -------------------------------------------------------------------
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​
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# -------------------------------------------------------------------
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# Global variables
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# -------------------------------------------------------------------
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fileSize = ""
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totalBits = 0
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networkSpeed = ""
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bitsPerSecond = 0.0
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downloadTime = 0.0
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​
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# -------------------------------------------------------------------
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# Subprograms
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# -------------------------------------------------------------------
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​
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# convert a string like "1.7 MiB" to the number of bits (e.g 14260634)
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def convertSizeToBits(pFileSize):
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  parts = pFileSize.split(" ")
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  quantity = float(parts[0])
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  unit = parts[1]
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  if unit == "B":
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    quantity *= 8
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  elif unit == "KiB":
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    quantity *= 8 * 1024
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  elif unit == "MiB":
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    quantity *= 8 * (1024 ** 2)
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  elif unit == "GiB":
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    quantity *= 8 * (1024 ** 3)
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  elif unit == "TiB":
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    quantity *= 8 * (1024 ** 4)
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  else:
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    print("Unknown unit, assuming you entered the number of bits")
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  return math.ceil(quantity)
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​
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# convert a string like "10 Mbps" to the number of bits per second (e.g. 10000000)
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def convertSpeedToBitsPerSecond(pSpeed):
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  parts = pSpeed.split(" ")
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  speed = float(parts[0])
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  unit = parts[1]
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  if unit == "Kbps":
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    speed *= 1000
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  elif unit == "Mbps":
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    speed *= (1000 ** 2)
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  elif unit == "Gbps":
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    speed *= (1000 ** 3)
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  elif unit == "Tbps":
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    speed *= (1000 ** 4)
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  else:
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    print("Unknown unit, assuming you entered the number of bits per second")
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  return speed
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​
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# convert a time in seconds like 0.3 to a human readable string (e.g "300 ms")
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def convertTime(pTimeInSeconds):
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  unit = "s"
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  duration = pTimeInSeconds
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  if duration < 1:
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    unit = "ms"
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    duration *= 1000
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  elif duration > 60:
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    unit = "mins"
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    duration /= 60
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  return "{:.1f} {}".format(duration, unit)
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# -------------------------------------------------------------------
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# Main program
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# -------------------------------------------------------------------
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​
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print("Download speed calculator")
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​
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# find the size of the file in bits
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fileSize = input("Enter file size (e.g. 1.7 MiB)")
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totalBits = convertSizeToBits(fileSize)
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print("Total number of bits: ", totalBits)
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​
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# find the network speed in bits per second
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networkSpeed = input("Enter network speed (e.g. 55 Mbps)")
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bitsPerSecond = convertSpeedToBitsPerSecond(networkSpeed)
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print("Total bits per second: ", bitsPerSecond)
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​
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downloadTime = totalBits / bitsPerSecond
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print("Download time:", convertTime(downloadTime))
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​
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# Challenges
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# 1) Replace every 1024 with a constant called BYTES_IN_KIBIBYTE
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# 2) Replace every 1000 with a constant called BYTES_IN_KILOBYTE
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# 3) Adjust convertTime to show very long times in hours rather than minutes