Itertools is a Python module that provide various functions that work on iterators to produce complex iterators. It makes the code faster, memory efficient and thus we see a better performance. This module is either used by themselves or in combination to form iterator algebra.
Note: For more information, refer to Python Itertools
Dropwhile()
The dropwhile()
function of Python returns an iterator only after the func
. in argument returns false
for the first time.
Syntax:
dropwhile(func, seq):
Example 1:
# Python code to demonstrate the working of # dropwhile() # Function to be passed # as an argument def is_positive(n):
return n > 0 value_list = [ 5 , 6 , - 8 , - 4 , 2 ]
result = list (itertools.dropwhile(is_positive, value_list))
print (result)
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Output:
[-8, -4, 2]
Example 2:
# Python code to demonstrate the working of # dropwhile() import itertools
# initializing list li = [ 2 , 4 , 5 , 7 , 8 ]
# using dropwhile() to start displaying after condition is false print ( "The values after condition returns false : " , end = "")
print ( list (itertools.dropwhile( lambda x : x % 2 = = 0 , li)))
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Output:
The values after condition returns false : [5, 7, 8]