Notes

1 Hello World!

Course link Girraffe Academy

• install python 3 and pycharm
• choose interpreter python 3
• create a python file
• print{“Hello, World!"}
• Set variables (easy and any where, could be rewrite) (xx = xx)
• is_Male = Ture / False (careful with the capital letter)

2 string

• string variables "”
• ex. abc = “string test”
• any marks in "" can be achieved by \
• string fuctions: abc.lower(), abc.upper(), abc.isupper(), combination is also ok
• lens(abc), abc[0], strat with 0, check the text, vs. abc. index(“t”), the first t position will be found. abc.replcace(“test”, “variable”)

3 number

• numbers
• basic calculation works, print(3 * (4 + 5))
• remainder, print(10 % 3)
• define number variable, my_num = 28
• convert number to string, str(my_num)
• print out only can excute for same variables
• ex, print(abc + my_num) will not work
• absolute value, abs(my_num)
• pow(3, 2), 3 *3
• max(2, 3), find the max one, vs. min(2, 3)
• round(3.2), get 3, round number
• import (external) python math (module): from math import *
• floor(3.8), ceil(3.8), sqrt(36)

4 input

• name = input(“Enter your name: “)
• age = input(“Enter your age: “)
• print (“Hello " + name + “! You are " + age + “.")
• multiple input available

5 calculator

• default input is considered as string, so by calcu, convert number.
• int(), float()
• num1 = input(“Enter a number: “)
• num1 = input(“Enter a number: “)
• result = float(num1) + float(num2)
• print(result)

6 mad libs game

• color = input(“Enter a color: “)
• plural_noun = input(“Enter a plural noun: “)
• celebrity = input(“Enter a celebrity: “)
• print(“Rose are " + color)
• print(plural_noun + " are blue”)
• print(“I love " + celebrity)

7 list

• friends = [“Kevin”, “Karen”, “Jim”, “Oscar”]

• print(friends[2])

• negative number also works [-1] is last one， [0] is the first one

• [1:3], only grab 1, and 2, not 3!

• list fuctions

• lucky_numbers = “[4, 8, 15, 16, 23, 42]”

• friends = [“Kevin”, “Karen”, “Jim”, “Oscar”]

• friends.extend(lucky_numbers) merge two list

• friends.append(“Creed”) add in the end

• friends.insert(1, “Kelly”) insert with position

• friends.remove(“Jim”)

• friends.clear()

• friends.pop() remove the last element

• friends.index(“Kevin”)

• friends.count(“Jim”)

• friends.sort() Alfabet and number order

• friends.reverse() reverse the order

• friends2 = friends.copy()

• print(friends[2])

8 tuples

• coordinates = (4, 5)

• tuple object does not support item assignment

• print(coordinate[1])

• list vs. tuple, [] vs. ()

• tuple is not mutable

9 functions

• c

MOOC Python网络爬虫与信息提取

1. requests
2. robots.txt
3. Beautiful Soup
4. Projects
5. Re
6. Scrapy

「 加个鸡腿！ 」

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