Python base

//this is my first day to study python, in order to review, every day i will make notes (2016/7/31)

1. In python , there are many bulit-in funcation. you can user follow to find out hou many built-in funcation:

dir(__builtins__)

if you want get BIF detail, you can use follow code:

help(……)    such as help(input),int()

2. In python, you should be care to indent, if not , it will appear a lots error.

such as follow ,because indent error ,it will appear an error:

temp = input(‘input a num you want:‘)
    guess = int(temp)
    if guess == 8:
    print(‘you are right‘)
    else:
           print(‘you are wrong‘)

3. In python , when you define variable ,uppercase and lowercase is different.

such as:

temp = ‘roy‘

Temp = ‘wyg‘

temp and Temp is not same variable

4. In python , if you want to user ‘ in a string ,you can user escape charcters : \

such as:

print(‘Let\‘s go!‘)

5. In python , origin string is userful , maybe the follow result is not  you except

such as :

str = ‘c:\now\data‘

print(str)

result is :

c:

ow\data

you can solve this proble by str = r‘c:\now\data‘ ,this code is equal to str = ‘c:\\now\\data‘

when you print(str), the result will be c:\now\data

6. In python , if a string , you want to change row ,you can user ‘‘‘  ,if you not user ‘‘‘ and change row ,it will appear an error

such as:

str = ‘‘‘this

is

me‘‘‘

print(str)

the result is :

this

is

me

7. import module , such as if you want  a rand num , range is 1-10 and type is int ,how to achieve it

import random

randnum = random.randint(1,10)