map

map(函数,可以迭代的对象)

# def f1(x):
# if x>2:
# return True
# else:
# return False
# ret = filter(f1,[0,1,2,3,4,5])
# for i in ret:
# print(i)

def f1(x):
return x+100
#ret = map(f1,[1,2,3,4,5])
ret = map(lambda x:x+100,[1,2,3,4,5,6,])
print(ret)
for i in ret:
print(i)










C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\python.exe “C:\Program Files\JetBrains\PyCharm 2017.2\helpers\pydev\pydevd.py” –multiproc –qt-support=auto –client 127.0.0.1 –port 1064 –file C:/Users/Administrator/PycharmProjects/py/recover.py
pydev debugger: process 4952 is connecting


Connected to pydev debugger (build 172.3317.103)
<map object at 0x02E71030>
101
102
103
104
105
106


Process finished with exit code 0

filter

Filter(函数,可以迭代的对象)

循环可以迭代的对象,获取每一个参数,函数(参数)

 
 

def f1(x):

return True

filter(f1,[11,22,33,44])

 
 


def f1(x):
if x % 2 == 0:
return True
else
:
return False

ret = list(filter(f1, [11, 22, 33, 44]))
print(ret)

ret2 = list(filter(lambda x: x % 2 == 0, [11, 22, 33, 44, 55, 66, ]))
print(ret2)

 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\python.exe “C:\Program Files\JetBrains\PyCharm 2017.2\helpers\pydev\pydevd.py” –multiproc –qt-support=auto –client 127.0.0.1 –port 10054 –file C:/Users/Administrator/PycharmProjects/py/filter_test.py

pydev debugger: process 892 is connecting

 
 

Connected to pydev debugger (build 172.3317.103)

[22, 44]

[22, 44, 66]

Process finished with exit code 0

eval

eval:可以执行一个字符串形式的表达式

exec:执行这人python代码,没返回值

comple编译代码

ret = eval(“1+2″)

print(ret)

ret = eval(”a+60“,{”a”:99})

3

Chr odr

C = chr(66)

print(c)

i=ord(“a”)

print(i)

 

#!/usr/bin/env python
#-*-coding:utf-8-*-
def f1():
return 123
print(f1())
f2 = lambda : 123
print(f2())

def f3(a1,a2):
return a1+a2
f4=lambda a1,a2:a1+a2
print(f3(1,2))
print(f4(2,3))

#all
i=oct(10)
print(i)
i=int(0x15)
print(i)
ii=int(0b110101010101)
print(ii)

i = int(“100”,base=13)
print(i)

内置函数

abs()

all()循环参数,如果每个元素都为真,那么all的返回值为真

any() 只有有一个真,则为真

r = all([True,True])

print(r)

每个元素都为真True

假,0,None “” [] () {}

print(bool(0))

print(bool(None))

print(bool(“”))

print(bool([]))

print(bool({}))

all([])

print(bool(()))

false

false