Python Day-List 理解-练习

fruits = ["apple", "banana", "cherry", "kiwi", "mango"]
newlist = []

for x in fruits:
  if "a" in x:
    newlist.append(x)

print(newlist)

fruits = ["apple", "banana", "cherry", "kiwi", "mango"]

newlist = [x for x in fruits if "a" in x]
print(newlist)

['apple', 'banana', 'mango']

l = [10,20,30,40]
newlist = []
#using normal loop
for num in l:
    newlist.append(num**2)
print(newlist)

#using loop in comprehensive way
newlist = [num**2 for num in l]
print(newlist)

[100, 400, 900, 1600]
[100, 400, 900, 1600]

#30,40
l1 = [10,20,30,40]
l2 = [30,40,50,60]
#normal method

for num in l1:
    for no in l2:
        if num== no:
            print(num,end=' ')
#comprehensive

print([num for num in l1 for no in l2 if num==no])

[30, 40]

l1 = [10,20,30,40]
l2 = [30,40,50,60]
#comprehensive
output = [num for num in l1 if num not in l2]

output = output + [num for num in l2 if num not in l1]
print(output)

#normal method
for num in l1:
    if num not in l2:
        print(num,end=' ')

for num in l2:
    if num not in l1:
        print(num,end=' ')

[10, 20, 50, 60]
10 20 50 60 

l1 = [1,2,3]
l2 = [5,6,7]

l = [(i,j) for i in l1 for j in l2 if i!=j]
print(l)

[(1, 5), (1, 6), (1, 7), (2, 5), (2, 6), (2, 7), (3, 5), (3, 6), (3, 7)]

s = "a1b2c3"

alpha_list = []
num_list = []

for letter in s:
    if letter.isalpha():
        alpha_list.append(letter)
    else:
        num_list.append(letter)

print("".join(alpha_list+num_list))

s = "a1b2c3"
letter=''.join([i for i in s if i.isalpha()])
no=''.join([i for i in s if i.isdigit()])

print(letter+no)

abc123

s = "a4k3b2"
i = 0 
while i<len(s):
    first = s[i]
    second = int(s[i+1])
    print(first, chr(ord(first)+second),sep='',end='')
    i+=2