17 tips for Python and 17 tips for Python

17 tips for Python and 17 tips for Python

1. Exchange Variables

Copy codeThe Code is as follows:
X = 6
Y = 5

X, y = y, x

Print x
>>> 5
Print y
>>> 6

2. The if statement is in the row

Copy codeThe Code is as follows:
Print "Hello" if True else "World"
>>> Hello

3. Connection

The last method below looks cool when binding two different types of objects.

Copy codeThe Code is as follows:
Nfc = ["Packers", "49ers"]
Afc = ["Ravens", "Patriots"]
Print nfc + afc
>>> ['Packers', '49ers', 'raws', 'pattern']

Print str (1) + "world"
>>> 1 world

Print '1' + "world"
>>> 1 world

Print 1, "world"
>>> 1 world
Print nfc, 1
>>> ['Packers', '49ers'] 1

4. computing skills

Copy codeThe Code is as follows:
# Round down
Print 5.0 // 2
>>> 2
# Power 5 of 2
Print 2 ** 5
> 32

Pay attention to the division of floating point numbers.

Copy codeThe Code is as follows:
Print. 3/. 1
>>> 2.9999999999999996
Print. 3 //. 1
>>> 2.0

5. Numerical Comparison

Copy codeThe Code is as follows:
X = 2
If 3> x> 1:
Print x
>>> 2
If 1 <x> 0:
Print x
>>> 2

6. Two lists are iterated simultaneously.

Copy codeThe Code is as follows:
Nfc = ["Packers", "49ers"]
Afc = ["Ravens", "Patriots"]
For teama, teamb in zip (nfc, afc ):
Print teama + "vs." + teamb
>>> Packers vs. Ravens
>>> 49ers vs. Patriots

7. List iteration with indexes

Copy codeThe Code is as follows:
Teams = ["Packers", "49ers", "Ravens", "Patriots"]
For index, team in enumerate (teams ):
Print index, team
>>> 0 Packers
>>> 1 49ers
>>> 2 Ravens
>>> 3 Patriots

8. List Derivation

If a list is known, the method for selecting an even number list is as follows:

Copy codeThe Code is as follows:
Numbers = [1, 2, 3, 4, 5, 6]
Even = []
For number in numbers:
If number % 2 = 0:
Even. append (number)

Replace the following

Copy codeThe Code is as follows:
Numbers = [1, 2, 3, 4, 5, 6]
Even = [number for number in numbers if number % 2 = 0]

9. dictionary Derivation

Copy codeThe Code is as follows:
Teams = ["Packers", "49ers", "Ravens", "Patriots"]
Print {key: value for value, key in enumerate (teams )}
>>>{ '49ers': 1, 'raws': 2, 'pattern': 3, 'packers': 0}

10. initialize the value of the list.

Copy codeThe Code is as follows:
Items = [0] * 3
Print items
>>> [0, 0]

11. Convert the list to a string

Copy codeThe Code is as follows:
Teams = ["Packers", "49ers", "Ravens", "Patriots"]
Print ",". join (teams)
>>> 'Packers, 49ers, Ravens, Patriots'

12. Retrieve elements from the dictionary

Do not use the following methods

Data = {'user': 1, 'name': 'max ', 'three': 4}
Try:
Is_admin = data ['admin']
Failed t KeyError:
Is_admin = False
Replace

Copy codeThe Code is as follows:
Data = {'user': 1, 'name': 'max ', 'three': 4}
Is_admin = data. get ('admin', False)

13. Obtain the sublist

Copy codeThe Code is as follows:
X = [1, 2, 3, 4, 5, 6]
# First 3
Print x [: 3]
>>> [1, 2, 3]
# Four in the middle
Print x [1: 5]
>>> [2, 3, 4, 5]
# Last 3
Print x [-3:]
>>> [4, 5, 6]
# Odd items
Print x [: 2]
>>> [1, 3, 5]
# Even items
Print x [1: 2]
>>> [2, 4, 6]

Fix FizzBuzz with 14.60 characters

Some time ago, Jeff Atwood promoted a simple programming exercise called FizzBuzz. The problem is referenced as follows:

Write a program, print the numbers 1 to, and print "Fizz" in multiples of 3 to replace this number, and print "Buzz" in multiples of 5 ", print "FizzBuzz" for numbers that are multiples of 3 and multiples of 5 ".
Here is a short way to solve this problem:

For x in range (101): print "fizz" [x % 3*4:] + "buzz" [x % 5*4:] or x

15. Set

Counter database used

Copy codeThe Code is as follows:
From collections import Counter
Print Counter ("hello ")
>>> Counter ({'l': 2, 'H': 1, 'E': 1, 'O': 1 })

16. iterative tools

Like the collections library, there is also a library called itertools

Copy codeThe Code is as follows:
From itertools import combinations
Teams = ["Packers", "49ers", "Ravens", "Patriots"]
For game in combinations (teams, 2 ):
Print game
>>> ('Packers', '49ers ')
>>> ('Packers', 'raws ')
>>> ('Packers', 'pattern ')
>>> ('49ers', 'raws ')
>>> ('49ers', 'pattern ')
>>> ('Raws', 'pattern ')

17. False = True

In python, True and False are global variables, so:

Copy codeThe Code is as follows:
False = True
If False:
Print "Hello"
Else:
Print "World"
>>> Hello

These are some of the commonly used Pyton tips I have summarized. They are suitable for beginners and I hope you will like them.