#lambda.py

# multiple arguments
g = lambda x,y: 3*x+1 + 2*y+10   #return one number
print(g(1,2))

g = lambda x,y: (3*x+1,2*y+10)   #return tuple
print(g(1,2))



# list argument
g = lambda x: [i**2 for i in x]    #return list
print(g([1,2,3,4]))

arithmetic_mean = lambda x: sum(x)/len(x)
print(arithmetic_mean([1,2,3,4]))


def product(nums):
    prod = 1
    for num in nums:
        prod *= num
    return prod

import math

geometric_mean = lambda x: math.pow(product(x) , 1/len(x))
print(geometric_mean([1,2,3,4]))

      
harmonic_mean = lambda x: len(x) / sum([1/i for i in x])
print(harmonic_mean([1,2,3,4]))


# sorting
s = "asdfBqweZrty"
print(sorted(s, key=lambda c: c.lower()))  #case-insensitive


#return sub_string of s and +/- surrounding
find = lambda s,subS,sur: s[s.find(subS)-sur:s.find(subS)+len(subS)+sur] if subS in s else None
alice = '''
Alice was beginning to get very tired of sitting by her sister
on the bank and of having nothing to do  once or twice she had
peeped into the book her sister was reading but it had no
pictures or conversations in it and what is the use of a book
thought Alice without pictures or conversation'''
print(find(alice.replace('\n',' '),'sister',3))