The comrehensions format is

**[*transform* *iteration* *filter* ]**.

Let's have some example.

# read a file line by line check whether or not "word" contains in each line (ignore case) print [ line.strip("\n").lower() for line in open("a.in") if "word" in line] # initialize array by square number print [i**2 for i in range(10)] # initialize array with tuples print [(i,i**2) for i in range(10)] # initialize array by odd number print [i for i in range(10) if i%2] words = ["Life", "is", "very", "easy", "Python"] # print first character of each word print [word[0] for word in words] # make all words to upper case print [word.upper() for word in words] # Sum each element of two array a = [1, 2, 3] b = [4, 5, 6] print [a[i]+b[i] for i in range(len(a))]

## 1 comments:

import math

N = 100

r = int(math.ceil(math.sqrt(float(N))))

primes = [x for x in range(2, N) if x not in [j for i in range(2, r) for j in range(i*2, N, i)]]

# prime generate using list comprehension

# It is not optimize code, Do not try with large value of N,

# N within 1000 is ok.

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