python_day3

01、编码

import sys
print(sys.getdefaultencoding())

s = "你哈"
s_gbk = s.encode("gbk")

print(s_gbk)
print(s.encode())

gbk_to_utf8 = s_gbk.decode("gbk").encode("utf-8")
print("utf8",gbk_to_utf8)

02、文件修改

import sys
f = open("yesterday2","r",encoding="utf-8")
f_new = open("yesterday2.bak","w",encoding="utf-8")

find_str = sys.argv[1]
replace_str = sys.argv[2]
for line in f:
    if find_str in line:
        line = line.replace(find_str,replace_str)
    f_new.write(line)
f.close()
f_new.close()

03、高阶函数

def add(a,b,f):
    return f(a)+f(b)

res = add(3,-6,abs)
print(res)

04、递归

def calc(n):
    print(n)
    if int(n/2) >0:
        return calc( int(n/2) )
    print("->",n)
    
calc(10)

05、进度条

import sys,time

for i in range(20):
    sys.stdout.write("#")
    sys.stdout.flush()
    time.sleep(0.1)

06、集合

list_1 = [1,4,5,7,3,6,7,9]
list_1 = set(list_1)

list_2 =set([2,6,0,66,22,8,4])
print(list_1,list_2)
'''
#交集
print(  list_1.intersection(list_2) )

#并集
print(list_1.union(list_2))

#差集 in list_1 but not in list_2
print(list_1.difference(list_2))
print(list_2.difference(list_1))

#子集
list_3 = set([1,3,7])
print(list_3.issubset(list_1))
print(list_1.issuperset(list_3))

#对称差集
print(list_1.symmetric_difference(list_2))

print("-------------")

list_4 = set([5,6,7,8])
print(list_3.isdisjoint(list_4)) # Return True if two sets have a null intersection.
'''


#交集
print(list_1 & list_2)
#union
print(list_2 | list_1)

#difference
print(list_1 - list_2) # in list 1 but not in list 2

#对称差集
print(list_1 ^ list_2)

list_1.add(999)
list_1.update([888,777,555])
print(list_1)

print(list_1.pop())
print(list_1.pop())
print(list_1.pop())
print(list_1.pop())

print(  list_1.discard(888)  )

07、with语句

import sys
#f = open("yesterday2","r",encoding="utf-8")

with open("yesterday2","r",encoding="utf-8") as f ,
      open("yesterday2", "r", encoding="utf-8") as f2:
    for line in f:
        print(line)

08、字符串

name = "my 	name is {name} and i am {year} old"

print(name.capitalize())
print(name.count("a"))
print(name.center(50,"-"))
print(name.endswith("ex"))
print(name.expandtabs(tabsize=30))
print(name[name.find("name"):])
print(name.format(name='alex',year=23))
print(name.format_map(  {'name':'alex','year':12}  ))
print('ab23'.isalnum())
print('abA'.isalpha())
print('1A'.isdecimal())
print('1A'.isdigit())
print('a 1A'.isidentifier()) #判读是不是一个合法的标识符
print('33A'.isnumeric())
print('My Name Is  '.istitle())
print('My Name Is  '.isprintable()) #tty file ,drive file
print('My Name Is  '.isupper())
print('+'.join( ['1','2','3'])  )
print( name.ljust(50,'*')  )
print( name.rjust(50,'-')  )
print( 'Alex'.lower()  )
print( 'Alex'.upper()  )
print( '
Alex'.lstrip()  )
print( 'Alex
'.rstrip()  )
print( '    Alex
'.strip()  )
p = str.maketrans("abcdefli",'123$@456')
print("alex li".translate(p) )

print('alex li'.replace('l','L',1))
print('alex lil'.rfind('l'))
print('1+2+3+4'.split('
'))
print('1+2
+3+4'.splitlines())
print('Alex Li'.swapcase())
print('lex li'.title())
print('lex li'.zfill(50))

print( '---')

08、文件

#data = open("yesterday",encoding="utf-8").read()
f = open("yesterday2",'a',encoding="utf-8") #文件句柄
#a = append 追加

f.write("
when i was young i listen to the radio
")
data = f.read()
print('--read',data)
f.close()


#f = open("yesterday2",'r+',encoding="utf-8") #文件句柄 读写
#f = open("yesterday2",'w+',encoding="utf-8") #文件句柄 写读
#f = open("yesterday2",'a+',encoding="utf-8") #文件句柄 追加读写
f = open("yesterday2",'wb') #文件句柄  二进制文件
f.write("hello binary
".encode())
f.close()

print(f.encoding)

#print(f.flush())
print(dir(f.buffer) )
#high bige

count = 0
for line in f:
    if count == 9:
        print('----我是分割线----------')
        count += 1
        continue
    print(line)
    count +=1

#low loop

for index,line in enumerate(f.readlines()):
    if index == 9:
        print('----我是分割线----------')
        continue
    print(line.strip())
#for i in range(5):
#    print(f.readline())

09、函数操作

import  time
def logger():
    time_format = '%Y-%m-%d %X'
    time_current = time.strftime(time_format)
    with open('a.txt','a+') as f:
        f.write('%s end action
' %time_current)

def test1():
    print('in the test1')

    logger()
def test2():
    print('in the test2')

    logger()
def test3():
    print('in the test3')
    logger()

test1()
test2()
test3()

10、函数一

#*args:接受N个位置参数，转换成元组形式
# def test(*args):
#     print(args)
#
# test(1,2,3,4,5,5)
# test(*[1,2,4,5,5])#  args=tuple([1,2,3,4,5])

# def test1(x,*args):
#     print(x)
#     print(args)
#
# test1(1,2,3,4,5,6,7)


#**kwargs：接受N个关键字参数，转换成字典的方式
# def test2(**kwargs):
#     print(kwargs)
#     print(kwargs['name'])
#     print(kwargs['age'])
#     print(kwargs['sex'])
#
# test2(name='alex',age=8,sex='F')
# test2(**{'name':'alex','age':8})
# def test3(name,**kwargs):
#     print(name)
#     print(kwargs)
#
# test3('alex',age=18,sex='m')

# def test4(name,age=18,**kwargs):
#     print(name)
#     print(age)
#     print(kwargs)
#
# test4('alex',age=34,sex='m',hobby='tesla')

def test4(name,age=18,*args,**kwargs):
    print(name)
    print(age)
    print(args)
    print(kwargs)
    logger("TEST4")



def logger(source):
    print("from %s" %  source)

test4('alex',age=34,sex='m',hobby='tesla')