Your Guide To Productive Python Programming

May 2nd 2021 new story

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Have you ever felt that you are not coding Python as productive as you want to be? Have you ever found yourself repeating the same statements consecutively but each with slight changes?

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Well then, is guide is for you. The beauty of Python is that it gives us several valuable constructs to avoid repetition and to do more work with less code.

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You may already know such gems as what I call the "two-variable swap trick" involving the use of tuples or the "multiple value input” trick that gets many variables from

input()

split(" ")

[::-1]

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Variable numbers of arguments

You might know that there are some C functions such as

printf()

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def fun1(*a):
    res=1
    for ele in a:
        res*=ele
    return res
ans=fun1(5,6,9,6,9,6,6)
print(ans)   # prints `524880`

(from 10 Python Tricks That Will Wow You)

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Here's another more organic example, a calculator that makes use of positional arguments:

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OP_ADD = 1
OP_SUBTRACT = 2
OP_MULTIPLY = 3
#...
def calculator(op, *var):
    if op == OP_ADD:
        a, b = *var
        return a + b
    elif op == OP_NEG:
        a = *var
        return -a
    #...

Selectively printing text

Have you ever found yourself writing code like this?

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if foo == True:
    print("All is well!")
else:
    print("We may have a problem")

You don't have to do that! This can be done in one line using the condensed form of the

if

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print("All is well!" if foo == True else "We may have a problem")

Make a table of element occurrences

By making use of the

count()

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Two-way comparisons

In Python, you can chain two less-than or greater-than operators to test whether a number is within a range. No more having to test them separately!

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if 1 < x < 10:
   #...

Enhanced tracing using

icecream

It's happened to most of us. The debugger goes kaput, and it forces us to sprinkle

print()

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That's where

icecream

icecream

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When you do call it with an argument, however, it will print the name and value of the variable you passed. It's convenient to avoid mass repetition from writing a bunch of your own

print()

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from icecream import ic 

def hello(user:bool):
    if user:
        ic()
    else:
        ic()

hello(user=True)

num1 = 30
num2 = 40 

ic(num1)
ic(num2)

(from Stop Using Print to Debug in Python. Use Icecream Instead)

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Antipatterns

Having said all that, make sure you avoid the following pitfalls while coding:

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• Using list comprehensions on a vast array. This will use unnecessarily large amounts of memory.
• Using

  range(len(<list>))

  for the iterator in

  for

  loops. This forces you to get the list length again using

  len()

  . It is better to use

  enumerate()

  in such scenarios to get both the value and index. Additionally, avoid using

  for i in ...

  syntax if you need indices in the loop.
• Using square brackets

  []

  to access dictionary keys if they may not exist. Instead of handling

  KeyError

  exceptions (and it's tempting to omit

  try

  groups when accessing random dictionary keys), use the

  get()

  method of dictionaries, which will return

  None

  if the key does not exist. The resulting

  if

  conditional is much easier to handle in code.

So as you just saw, Python is a very rich language that gives you more straightforward ways of programming the same thing. And where the functionality is not built-in, there is usually a PyPI module that does it.

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