#
#
#
# '' 'List' ''
## Definition: [], the plurality of values can be stored any data type, separated by commas
# # Define a list of students, storing more than one student
# List ([ 'dog is better than great,' 'than the Sun,' 'Wang Jie'])
# Students = [ 'second child', 'baby']
# Print (students [1]) # doll
#
# Student_info = [ 'Yangmeikeng', 45 'MALE', [ 'drink', 'food'], 45]
# Print (student_info [3]) # all interested
# Print (student_info [3] [1]) # the second hobby
#
# #add to
# Student_info.append ( 'Hefei')
# print(student_info)
#
# # Delete
# Of student_info [2]
# print(student_info)
# #I get a list of index values
# print(student_info.index(45))
## 2 Number obtain a list of values
# print(student_info.count(45))
# # 3 value, default take the last value in the list, similar to the deleted
# # If the pop () wrote in the index, then take the value of the index
# student_info.pop()
# print(student_info)
# # Remove the list index value of 2, and assigned to the sex variable name
# sex=student_info.pop(2)
# print(sex)
# print(student_info)
# # 4 removed, the value of a first value in the list removed
# student_info.remove(45)
# print(student_info)
#
# Name = student_info.remove ( 'Yangmeikeng')
# print(name) #None
# print(student_info)
#
# # 5. Interpolated values
# Student_info.insert (3, 'Hefei')
# print(student_info)
#
# # 6.extend merge list
# Student_info2 = [ 'dog than Wei', 46, 'female', [ 'drink 1', '2 gourmet']]
# Student_info1 = [ 'Yin Haoqing', 46, 'female', [ 'drink', 'food']]
# student_info1.extend(student_info2)
# print(student_info1)
# Tuple:
#Define:
# In () may be any type storing a plurality of values, separated by commas
# Note: tuples and lists different, can only initialize the value at the time of definition, can not be modified
# Advantage: occupies minimal memory resources to be smaller than the list
# Tuple ((1,2,3, 'five', 'six'))
# Tuple1 = (1,2,3, 'five', 'six')
# print(tuple1)
#
# for line in tuple1:
# print(line)
# print(line,end='_')
"""""
'''
Dictionary type:
effect:
In the {}, separated by commas can store a plurality of values,
Access to key-value, high value of speed.
definition:
key must be immutable type, value may be any type
'''
# dict1 = dict({'age': 18, 'name': 'tank'})
# dict1 = {'age': 18, 'name': 'tank'}
# print(dict1) # {'age': 18, 'name': 'tank'}
# print(type(dict1)) # <class 'dict'>
# Values, Dictionary name + [], brackets write value corresponding key
# print(dict1['age'])
# Master priority actions:
# 1, the access key press value: deposit may be desirable
# Deposit a level: 9 to the value of the dictionary dict1
# dict1['level'] = 9
# print(dict1) # {'age': 18, 'name': 'tank', 'level': 9}
# print(dict1['name']) # tank
#
# # 2, the length len
#
# # 3, members and not in operation in only judge the dictionary key
# print('name' in dict1) # True
# print('tank' in dict1) # False
# print('tank' not in dict1) # True
#
# # 4, delete
# del dict1['level']
# print(dict1) # {'age': 18, 'name': 'tank'}
#
# # 5, key Keys (), the value of values (), on the key-value items ()
# # Get a dictionary of all key
# print(dict1.keys())
# # Get all the values values in the dictionary
# print(dict1.values())
# # Get all the items in the dictionary
# print(dict1.items())
# 6, circulation
# Loop through the dictionary all the key
# for key in dict1:
# print(key)
# print(dict1[key])
# get
dict1 = {'age': 18, 'name': 'tank'}
# print(dict1.get('age'))
# [] Values
# print(dict1['sex']) # KeyError: 'sex'
# Get values
print(dict1.get('sex')) # None
# If no sex, to set a default value
print(dict1.get('sex', 'male'))
'''
File handling:
open()
Write file
wt: write text
Reading file
rt: Reading text
Additional write file
at: Append text
Note: You must specify character encoding, in what way to write
In what way will be open. Such as: utf-8
Python file execution process:
1. first start the python interpreter, loaded into memory.
2. Load written python files to the interpreter.
3. Detection python syntax to execute code.
SyntaxError: syntax error!
Open the file will have two resources:
1.python program
2. Open the file operating system
'''
# Write text files
Absolute path to the file: a parameter #
Mode mode operation file: # Parameter Two
# Three parameters: encoding specified character encoding
# f = open('file.txt', mode='wt', encoding='utf-8')
# f.write('tank')
# F.close () # close the operating system files resources
# Read a text file r == rt
# f = open('file.txt', 'r', encoding='utf-8')
# print(f.read())
# f.close()
#
#
## additional write text files
# a = open('file.txt', 'a', encoding='utf-8')
# A.write ( '\ n HEFEI')
# a.close()
'''
File processing of context management.
with open() as f "句柄"
'''
# Write
# with open('file1.txt', 'w', encoding='utf-8') as f:
# F.write ( 'Murphy's Law')
#
# # Reading
# with open('file1.txt', 'r', encoding='utf-8') as f:
# res = f.read()
# print(res)
#
# # add to
# with open('file1.txt', 'a', encoding='utf-8') as f:
# F.write ( 'Siege')
# # f.close()
'''
For pictures, audio, video, reading and writing
rb mode, read binary not necessary to specify the character encoding
'''
# Read photo cxk.jpg
with open('cxk.jpg', 'rb') as f:
res = f.read()
print(res)
jpg = true
# The cxk.jpg binary stream file written cxk_copy.jpg
with open('cxk_copy1.jpg', 'wb') as f_w:
f_w.write(jpg)
'''
with managing multiple files
'''
# To manage two f_r open file handles opened through with, f_w
with open('cxk.jpg', 'rb') as f_r, open('cxk_copy2.jpg', 'wb') as f_w:
# Handle to the picture by f_r binary stream read out
res = f_r.read()
# By f_w handle the flow picture binary file written cxk_copy.jpg
f_w.write(res)
'''
Three ways function declaration
1 no reference functions do not require the external input parameter
There are 2 function parameters
3. Empty function
'''
''''''
'''
def function name (parameter 1, parameter 2 ...):
"" "Note: Statement function" ""
Logic code
return return value
def: defind definition.
Function name: must see its name knowing Italian.
(): Receiving the incoming external parameters.
Notes: used to declare the action function.
return: the return value to the caller.
'''
'''
Three forms defined functions:
1. The no-argument function
Not need to receive incoming external parameters.
2. Reference function
Need to receive external incoming parameters.
3. Empty function
pass
Function call:
Function name + () call
'''
# # 1 no-argument function
# def login():
# User = input ( 'Please enter your user name') .strip ()
# Pwd = input ( 'Please enter your password') .strip ()
#
# if user == 'tank' and pwd == '123':
# print('login successful!')
#
# else:
# print('login error!')
#
#
# # Memory address of the function
# print(login)
#
#
# # Function call
# login()
# 2. Reference function
# Username, password used to receive an external incoming value
# def login(username, password):
# User = input ( 'Please enter your user name') .strip ()
# Pwd = input ( 'Please enter your password') .strip ()
#
# if user == username and pwd == password:
# print('login successful!')
#
# else:
# print('login error!')
#
#
# # Function call
If the function ## needs to receive parameters when defining a caller must pass through their participation
# login('tank', '123')
# 3 Empty function
'''
ATM：
1. Log
2. Registration
3. Withdraw
4. Withdrawal
5. Transfer
6. Repayment
'''
# # Log function
# def login():
## representatives to do nothing
# pass
#
#
# # Registration function
# def register():
## representatives to do nothing
# pass
#
#
# # Payment function
# def repay():
# pass
# ...
'''
Function parameters:
'''
During the definition phase #: x, y call parameter.
# def func(x, y): # x, y
# Print (x, y)
#
# # Call the stage: 10, 100 called the argument.
# func(10, 100)
# '''
# Positional parameters:
Location parameter #
Position # argument
# Eleven must pass parameters by position.
# '''
During the definition phase ##: position parameter
# def func(x, y): # x, y
# Print (x, y)
# #
# # # Call the stage: 10, 100, said location argument.
# func(10, 100) # 10 100
#
# '''
# Keyword arguments:
# Keyword arguments
# Pass parameters by keyword.
# '''
## position parameter x, y
# def func(x, y):
# Print (x, y)
#
# # Call stage: x = 10, y = 100 call key parameter.
# func(y=111, x=10) # 10 111
# No less Biography
# Func (y = 111) # error TypeError
# No more pass
(Y = 111, x = 222, z = '333') # func # error TypeError
'''
Default parameters:
During the definition phase, set a default value for the parameter
'''
# def foo(x=10, y=20):
# Print (x, y)
#
## does not pass parameters, the default parameter
# foo()
#
# # Pass parameters using the parameters passed
# foo(200, 300)
Nested function is defined:
Defined function within the function.
Function object:
Memory address of a function called a constructor object.
Function namespace:
Built-in:
python parser comes with both called "built-in namespace."
Global:
All wore head to write variables, functions ... are called "full name space."
Local:
Within the definition of the function are called "local name space."
Namespace load order:
Built----> Global ---> Local
Namespace search order:
Local ---> Global ---> Built
'''
# Nested definitions function
def func1():
print('from func1...')
def func2():
print('from func2...')
# Function object
print(func1)
def f1():
pass
def f2():
pass
dic1 = {'1': f1, '2': f2}
choice = input ( 'select numbers:')
if choice == '1':
print(dic1[choice])
dic1[choice]()
elif choice == '2':
print(dic1[choice])
dic1[choice]()
x = 10
# Namespaces
# Nested definitions function
def func1():
# x = 20
print('from func1...')
print (x) # error
x = 30
def func2():
print('from func2...')
func1 ()