CS50P 4_Library

Modules

A module is a file containing Python definitions and statements.

filename.py --> filename is the module name

__name__ is the global variable of module name

Python 標準函式庫

Random Module

Generate pseudo-random numbers

using module

import random # import random package
print(random.random())
coin = random.choice(["heads", "tails"])
print(coin)
# import specific module in random
from random import random, choice 
print(random())
coin = choice(["heads", "tails"])
print(coin)
from random import * # import all module in random
print(random())
coin = choice(["heads", "tails"])
print(coin)

random() 產生 [0.0, 1.0)之間的隨機浮點數

from random import random
for i in range(5):
    print(f"random() {random()}")
random() 0.7793488239788828
random() 0.869568326885313
random() 0.8821685702670976
random() 0.9777859355580868
random() 0.006675999828335

randint(a, b) 產生一個[a, b]區間內的隨機整數。

import random
for i in range(5):
    number = random.randint(1,10)
    print(number)
3
5
7
10
3

random.shuffle(x) 使序列 x 重新隨機排列

import random
cards = ["acce","jack", "queen", "king", "ghost"]
print(f"original {cards}")
random.shuffle(cards)
print(f"shuffled {cards}")
original ['acce', 'jack', 'queen', 'king', 'ghost']
shuffled ['king', 'ghost', 'queen', 'jack', 'acce']

random.choice(x) 從序列 x 中隨機取出一個元素

import random
for i in range(3):
    fruit = rendom.choice(['apple', 'pear', 'banana'])
    print(f"You need {fruit}")
You need pear
You need banana
You need apple

random.sample(x, k) 從序列 x 中隨機取出k個元素

import random
cities = ["台北", "桃園", "新竹", "台中", "台南"]
for i in range(1,5):
    if i == 1:
        print(f"selec {i} city   {random.sample(cities, i)}")
    else:
        print(f"selec {i} cities {random.sample(cities, i)}") 
selec 1 city   ['桃園']
selec 2 cities ['台中', '新竹']
selec 3 cities ['台南', '台北', '台中']
selec 4 cities ['台南', '新竹', '桃園', '台北']

sys.argv 命令列參數

python test.py aaa 123 ccc
aaa 123 ccc --> 命令列參數

import sys
# 查看 sys.argv 列表內容
print("sys.argv 內容:", sys.argv)
# 第 1 個參數
print("第 1 個參數:", sys.argv[1])
python test.py aaa 123 ccc
sys.argv 內容: ['test.py', 'aaa', '123', 'ccc']
第 1 個參數: aaa

IndexError

import sys
# 查看 sys.argv 列表內容
print("sys.argv 內容:", sys.argv)
# 第 1 個參數
print("第 1 個參數:", sys.argv[1])
$python test.py
sys.argv 內容: ['test.py']
Traceback (most recent call last):
  File "/workspaces/87635444/test/libraries/test.py", line 5, in <module>
    print("第 1 個參數:", sys.argv[1])
IndexError: list index out of range

catch IndexError

import sys
# 查看 sys.argv 列表內容
print("sys.argv 內容:", sys.argv)
try:
    # 第 1 個參數
    print("第 1 個參數:", sys.argv[1])
except IndexError:
    print("命令列參數太少")
$ python test.py
sys.argv 內容: ['test.py']
命令列參數太少

檢查命令列參數的個數

import sys

if len(sys.argv)<2:
    print("Too few arguments")
elif len(sys.argv)>2:
    print("Too many arguments")
else:
    print("hello, my name is", sys.argv[1])
$ python test1.py
Too few arguments
$ python test1.py Ted
hello, my name is Ted
$ python test1.py Ted John
Too many arguments

Install package

import cowsay
import sys

if len(sys.argv) == 2:
    cowsay.cow("hello, " + sys.argv[1])
$ python cowsay1.py 
Traceback (most recent call last):
  File "/workspaces/87635444/test/libraries/cowsay1.py", line 3, in <module>
    import cowsay
ModuleNotFoundError: No module named 'cowsay'

install cowsay package

$ pip install cowsay
Defaulting to user installation because normal site-packages is not writeable
Collecting cowsay
  Downloading cowsay-5.0.tar.gz (25 kB)
  Preparing metadata (setup.py) ... done
Building wheels for collected packages: cowsay
  Building wheel for cowsay (setup.py) ... done
  Created wheel for cowsay: filename=cowsay-5.0-py2.py3-none-any.whl size=25707 sha256=b7b6c79d001b61e366e77574029aa4390c449dfae48ad63707bac412efbd8729
  Stored in directory: /tmp/pip-ephem-wheel-cache-mwurcbqt/wheels/5b/15/b9/15cb7194fd1eae6f630f6d7946fc5160b096a92eafb685c2dd
Successfully built cowsay
Installing collected packages: cowsay
Successfully installed cowsay-5.0

cowsay.cow

import cowsay
import sys

if len(sys.argv) == 2:
    cowsay.cow("hello, " + sys.argv[1])
$ python cowsay1.py Ted
  __________
| hello, Ted |
  ==========
          \
           \
             ^__^
             (oo)\_______
             (__)\       )\/\
                 ||----w |
                 ||     ||
                 

cowsay.tux

import cowsay
import sys

if len(sys.argv) == 2:
    cowsay.tux("hello, " + sys.argv[1])
test/libraries/ $ python cowsay2.py Ted
  __________
| hello, Ted |
  ==========
               \
                \
                 \
                  .--.
                 |o_o |
                 |:_/ |
                //   \ \
               (|     | )
              /'\_   _/`\
              \___)=(___/

Install Request Package

pip install requests

using Requests method

import requests
web = requests.get('https://water.taiwanstat.com/')  # 使用 get 方法
print(web.text)    # 讀取並印出 text 屬性
test/libraries/ $ python request.py
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"lang="zh-TW">
<head><meta property="og:title" content="台灣水庫即時水情">
....

Request json

import sys
import requests

if len(sys.argv) != 2:
    sys.exit()

response = requests.get(
    "https://itunes.apple.com/search?entity=song&limit=1&term=" + sys.argv[1]
)
print(response.json())

json.dumps

import json
import sys
import requests

if len(sys.argv) != 2:
    sys.exit()

response = requests.get(
    "https://itunes.apple.com/search?entity=song&limit=1&term=" + sys.argv[1]
)
print(json.dumps(response.json(), indent=2))

json.dumps

test/libraries/ $ python itune2.py jazz
{
  "resultCount": 1,
  "results": [
    {
      "wrapperType": "track",
      "kind": "song",
      "artistId": 161541223,
      "collectionId": 1467951962,
      "trackId": 1467952309,
      "artistName": "Gotye",
      "collectionName": "Making Mirrors (Deluxe Version)",
      "trackName": "Somebody That I Used to Know (feat. Kimbra)",
      "collectionCensoredName": "Making Mirrors (Deluxe Version)",
      "trackCensoredName": "Somebody That I Used to Know (feat. Kimbra)",
      "artistViewUrl": "https://music.apple.com/us/artist/gotye/161541223?uo=4",
      "collectionViewUrl": "https://music.apple.com/us/album/somebody-that-i-used-to-know-feat-kimbra/1467951962?i=1467952309&uo=4",
      "trackViewUrl": "https://music.apple.com/us/album/somebody-that-i-used-to-know-feat-kimbra/1467951962?i=1467952309&uo=4",
      "previewUrl": "https://audio-ssl.itunes.apple.com/itunes-assets/AudioPreview125/v4/a5/ff/2f/a5ff2fdd-11b3-698f-67e6-f49cad28df6e/mzaf_15135349959596902883.plus.aac.p.m4a",
      "artworkUrl30": "https://is2-ssl.mzstatic.com/image/thumb/Music125/v4/32/41/fe/3241fe70-3529-2060-7212-48cd0cccbe6e/11UMGIM19347.rgb.jpg/30x30bb.jpg",
      "artworkUrl60": "https://is2-ssl.mzstatic.com/image/thumb/Music125/v4/32/41/fe/3241fe70-3529-2060-7212-48cd0cccbe6e/11UMGIM19347.rgb.jpg/60x60bb.jpg",
      "artworkUrl100": "https://is2-ssl.mzstatic.com/image/thumb/Music125/v4/32/41/fe/3241fe70-3529-2060-7212-48cd0cccbe6e/11UMGIM19347.rgb.jpg/100x100bb.jpg",
      "collectionPrice": 16.99,
      "trackPrice": 0.69,
      "releaseDate": "2011-07-05T12:00:00Z",
      "collectionExplicitness": "notExplicit",
      "trackExplicitness": "notExplicit",
      "discCount": 1,
      "discNumber": 1,
      "trackCount": 12,
      "trackNumber": 3,
      "trackTimeMillis": 244973,
      "country": "USA",
      "currency": "USD",
      "primaryGenreName": "Alternative",
      "isStreamable": true
    }
  ]
}

get attribute from jason

import json
import sys
import requests

if len(sys.argv) != 2:
    sys.exit()

response = requests.get(
    "https://itunes.apple.com/search?entity=song&term=" + sys.argv[1]
)
o = response.json()
for result in o["results"]:
    print(result["trackName"])

get attribute from jason

$ python itune2.py jazz
Somebody That I Used to Know (feat. Kimbra)
Bad Day
Home
What a Wonderful World
Jazz
Feeling Good
The Way You Look Tonight
...

__name__

tools.py
def main():
    print(f"tolols test {tool_1()}")
    print(f"tolols test {tool_2()}")
 
def tool_1():
    return "you use tool1"
def tool_2():
    return "you use tool2"

main()
print(f"tools.py __name__ is {__name__}")
$ python tools.py
tolols test you use tool1
tolols test you use tool2
tools.py __name__ is __main__

use tools module

use_tools.py
import tools
print(f"use_tools  {tools.tool_1()}")
test/libraries/ $ python use_tools.py 
tolols test you use tool1
tolols test you use tool2
tools.py __name__ is __main__
use_tools you use tool1

prevent use_tool run tha main()

def main():
    print(f"tolols test {tool_1()}")
    print(f"tolols test {tool_2()}")
 
def tool_1():
    return "you use tool1"
def tool_2():
    return "you use tool2"

if __name__ == '__main__':
    main()
print(f"tools.py __name__ is {__name__}")
test/libraries/ $ python use_tools.py 
tolols test you use tool1
tolols test you use tool2
tools.py __name__ is __main__

use tools module

use_tools.py
import tools
print(f"use_tools  {tools.tool_1()}")
$ python use_tools.py 
__name__ is tools
you use tool1

request example

臺灣證券交易所 每日收盤行情

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