python基础五

#rb模式
f = open('test1.py','rb') #b的方式不能指定编码
data = f.read()
print(data)
print(data.decode('utf-8'))
#wb模式
g = open('test2.py','wb')
g.write(bytes('111\n',encoding='utf-8'))
g.write('峰峰'.encode('utf-8'))
#ab模式 append缩写表示在最后追加
s = open('test2.py','ab')
s.write(bytes('111\n',encoding='utf-8'))
s.write('xiaoming'.encode('utf-8'))

f = open('a.txt','r',encoding='utf8')
data = f.read()
print(data)
print(f.closed)
print(f.encoding)

error = f.errors
print(error)

f.flush()
f.name
#告诉你当前位置在哪里，按照字节来读
f.readline()
print(f.tell())
#控制光标的移动
f.seek(3)
print(f.tell())
#read是按照字符进行读，而其他的是按照字节进行读
newdata = f.read(1)
print(newdata)
#表示字节截取10个字节
f.truncate(10)

a = [1,2,3]
for i in a:
    print(i)

x = 'hello'
print(dir(x))

iter_a = a.__iter__()
print(iter_a.__next__())

index = 0
while index < len(a):
    print(a[index])
    index+=1
diddai_l = a.__iter__()


while True:
    try:
        print(diddai_l.__next__())
    except StopIteration:
        print('执行完毕')
        break
#三元表达式
name = 'a'
res ='c' if name == 'a' else 'b'
print(res)

#列表解析
egg_list = []
for i in range(10):
    egg_list.append('鸡蛋%s' %i)
print(egg_list)

new_list = ['鸡蛋%s' %i for i in range(10)]
new_list = ['鸡蛋%s' %i for i in range(10) if i < 5]
print(new_list)
#生成器表达式
laomuji = ('鸡蛋%s' %i for i in range(10))
print(laomuji)
print(next(laomuji))
print(next(laomuji))
print(next(laomuji))

def test():
    yield 1
    yield 2
    yield 3
    yield 4
g= test()
print(g)
print(next(g))
print(next(g))

second_list = [1,2,3,4]
print(sum(second_list))

#浅拷贝
s = [[1,2,3],'alex','alvin']
s1 = s.copy()
s1[0][0] = 8
print(s1)
print(s)
#深拷贝
import copy
snew = [[1,2,3],'alex','alvin']
s2= copy.deepcopy(snew)
s2[0][0] = 999
print(snew)
print(s2)

#集合的创建
a = [1,3,4]
b = list([4,5,6])
print(a)
print(b)
#无序 去重复
s = set('fengfeng')
sm = ['aleven','ee','aleven']
print(set(sm))
print(s)
for i in s:
   print(i)