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| -rw-r--r-- | python.html.markdown | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/python.html.markdown b/python.html.markdown index 49b46711..967c2bd7 100644 --- a/python.html.markdown +++ b/python.html.markdown @@ -655,6 +655,22 @@ def create_adder(x): add_10 = create_adder(10) add_10(3) # => 13 +# Closures in nested functions: +# We can use the nonlocal keyword to work with variables in nested scope which shouldn't be declared in the inner functions. +def create_avg(): + total = 0 + count = 0 + def avg(n): + nonlocal total, count + total += n + count += 1 + return total/count + return avg +avg = create_avg() +avg(3) # => 3.0 +avg(5) # (3+5)/2 => 4.0 +avg(7) # (8+7)/2 => 5.0 + # There are also anonymous functions (lambda x: x > 2)(3) # => True (lambda x, y: x ** 2 + y ** 2)(2, 1) # => 5 |