使用两个 for 循环的列表理解

Question

letters = list('xyz')
pattern = []
for i in range(len(letters)):    
       for j in range(1,5):     
           pattern.append(letters[i]*j)
pattern = ['x', 'xx', 'xxx', 'xxxx', 'y', 'yy', 'yyy', 'yyyy', 'z', 'zz', 'zzz', 'zzzz']

How can i write this code in list comprehension format?

Answer 1

You have most of your building blocks, just got to piece it together!

letters = list('xyz')
pattern = []

[pattern.append(letters[i]*j) for i in range(len(letters)) for j in range(1,5)]

print(pattern)
['x', 'xx', 'xxx', 'xxxx', 'y', 'yy', 'yyy', 'yyyy', 'z', 'zz', 'zzz', 'zzzz']

Answer 2

[i*j for i in 'xyz' for j in range(1,5)]

Answer 3

For output:

['x','y','z','xx','yy','zz','xxx','yyy','zzz']

code:

[l*i for l in 'xyz' for i in range(1,4)]

For output:

['x','xx','y','yy','z','zz']

code:

[l*i for i in range(1,3) for l in 'xyz'] 

Answer 4

for output

['x', 'xx', 'xxx', 'xxxx', 'y', 'yy', 'yyy', 'yyyy', 'z', 'zz', 'zzz', 'zzzz']

code ---

[i*j for i in 'xyz' for j in range(1,5)]

for output

['x', 'y', 'z', 'xx', 'yy', 'zz', 'xxx', 'yyy', 'zzz', 'xxxx', 'yyyy', 'zzzz']

code---

[i*j for j in range(1,5) for i in 'xyz'] 

Just interchange i,j