if __name__ == "__main__":

# The map() function applies a given function to each item of an iterable (list, tuple etc.)

# and returns a list of the results.

# tutorial_1

numbers = (1, 2, 3, 4)

# lambda often used in like filter(), map() and reduce().

result = map(lambda x: x * x, numbers)

print('result: {}'.format(result))

# filter object (ref. filter.py Compare the difference)

data = [

{'key': 'a', 'value': 1},

{'key': 'b', 'value': 2},

{'key': 'c', 'value': 3},

{'key': 'd', 'value': 4},

{'key': 'e', 'value': 4},

]

data_items = map(lambda x: x['value'], data)

print('data_items: {}'.format(data_items))

print('data_items_distinct: {}'.format(set(data_items)))

# tutorial_2

str_num = '1,2,3,4,5,6,7,8,9,10,11'

int_seqs = list(map(int, str_num.split(','))) # python3

# int_seqs = map(int, str_num.split(',')) # python2

print(isinstance(int_seqs, list))

for seq in int_seqs:

print(isinstance(seq, int))

print(seq)

# tutorial_3

pattern = 'abcidkeujaddcsjb'

print(list(map(pattern.find, pattern)))