2.1

# lst=['asdgg','as','drtysr']

# lst2=[i.upper()  for i in lst if len(i) >3 ]

# print(lst2)

# 2.2

# tu=[(x,y) for x in range(6) if x%2==0 for y in range(6) if y%2==0]

# print(tu)

#

# 2.3

# M=[[1,2,3],[4,5,6],[7,8,9]]

# a=[i[2] for i in M]

# print(a)

#

# 2.4

# a=[i**2 for i in range(50 ) if i %3==0]

# print(a)

#

# 2.5

# a=['python%s期' % i for i in range(1,11)]

# print(a)

#

# 2.6

# a=[(i,i+1) for i in range(6)]

# print(a)

#

# 2.7

# a=[i for i in range(0,20,2)]

# print(a)

#

# 2.8

# l1=['alex','wusir','老男孩','太白']

# a=[(l1[i]+str(i)) for i in range(4)]

# print(a)

#

# 2.9

# x={

#     'name':'alex',

#     'values':[{'timestamp':1517991992.94,'values':100},

#               {'timestamp':1517992000.94,'values':300},

#               {'timestamp':1517992014.94,'values':300},

#               {'timestamp': 1517992744.94, 'values': 350},

#               {'timestamp': 1517992800.94, 'values': 280},

#

#               ]}

# a=[[i['timestamp'],i['values']] for i in x['values']]

# print(a)