Basic grammar

data type

python is a weak data type language. When assigning a value, we do not need to declare the data type first, which is determined by the assigned value. There are several types:

    integer
    float
    Character string
    Boolean value
    Null value None

Conditional statement

    age = 3
    if age >= 18:
        print('adult')
    elif age >= 6:
        print('teenager')
    else:
        print('kid')

Loop statement

    names = ['Michael', 'Bob', 'Tracy']
    for name in names:
        print(name)

How do I access list values through indexes like any other programming language?

    names = ['Michael', 'Bob', 'Tracy']
    for i in range(0,len(names)):
        print(names[i])

Other cycles

    n = 1
    while n <= 100:
        print(n)
        n = n + 1
    print('END')

break and continue are similar to other languages, so we won't repeat them.

list

There is no such noun as array in python. Instead, list and tuple are used. The difference is that list is variable and tuple is immutable. We can use the help function to view the list method
Example

    classmate = ['johnw',"jack","tom","michael"]
    # Last element of pop-up list: michael
    p = classmate.pop() 
    print("pop Return: ",p)
    print("pop The following list is: ",classmate)
    
    # End element add
    p1 = classmate.append("mary")
    print("append Return: ",p1)
    print("append The following list is: ",classmate)
    
    # copy list
    p3 = classmate.copy()
    print("copy Return: ",p3)
    print("copy The following list is: ",classmate)
    
    # count returns the number of an element in the list
    p4 = classmate.count('johnw')
    print("count Return: ",p4)
    print("count The following list is: ",classmate)
    
    # Index find the index of the element
    p5 = classmate.index("jack",1)
    print("index Return: ",p5)
    
    # remove element
    p6 = classmate.remove("johnw")
    print("p6 Return: ",p6)
    print("remove The following list is: ",classmate)
    
    # reverse and sort
    a1 = [2,3,51,4,6,2,7,8]
    a1.sort()
    print("sort after a1 For:",a1)
    a1.reverse()
    print("reverse after a1 by: ",a1)
    
    # Clear list elements
    p2 = classmate.clear()
    print("clear Return: ",p2)
    print("clear The following list is: ",classmate)

dict dictionary

Dictionary is a common data structure. Using key value method to search is very fast. It is a data structure that uses space for time. The advantage is that both search and insert are fast, and the disadvantage is that it will occupy a lot of memory

insert values

test = {} 
test["Hello"] = "world"

lookup

test.get("Hello") 
test["Hello"]

Key value cycle

for key,value in test.items():
    print("key===>",key)
    print("value===>",value)

Key cycle

for key in test.keys():
    print("key: ,key)  

Value cycle

for value in test.values():
     print("value: ",value)

Key update

>>> a={"a":1,"b":2}
>>> a.update({"c":3})
>>> a
{'a': 1, 'b': 2, 'c': 3}