# 17 Python tips for sharing _python

Source: Internet
Author: User
Tags in python

1. Exchange variables

Copy Code code as follows:

x = 6
y = 5

X, y = y, X

Print X
>>> 5
Print Y
>>> 6

2.if statements in rows

Copy Code code as follows:

Print "Hello" if True else "world"
>>> Hello

3. Connection

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

Copy Code code as follows:

NFC = ["Packers", "49ers"]
AFC = ["Ravens", "patriots"]
Print NFC + AFC
>>> [' Packers ', ' 49ers ', ' Ravens ', ' patriots ']

Print str (1) + World
>>> 1 World

print ' 1 ' + "world"
>>> 1 World

Print 1, "World"
>>> 1 World
Print NFC, 1
>>> [' Packers ', ' 49ers '] 1

4. Computational skills

Copy Code code as follows:

#向下取整
Print 5.0//2
>>> 2
# 2 of the 5-time Square
Print 2**5
>> 32

Note The division of floating-point numbers

Copy Code code as follows:

Print. 3/.1
>>> 2.9999999999999996
Print. 3//.1
>>> 2.0

5. Numerical comparison

Copy Code code as follows:

x = 2
If 3 > x > 1:
Print X
>>> 2
If 1 < x > 0:
Print X
>>> 2

6. Two List simultaneous iterations

Copy Code code 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 iterations with indexes

Copy Code code 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

A list is known, and the brush picks up the sequence of even lists:

Copy Code code as follows:

numbers = [1,2,3,4,5,6]
even = []
For number in numbers:
If number%2 = 0:
Even.append (number)

Copy Code code as follows:

numbers = [1,2,3,4,5,6]
even = [number for number in numbers if number%2 = 0]

9. Dictionary derivation

Copy Code code as follows:

Teams = ["Packers", "49ers", "Ravens", "patriots"]
Print {Key:value for value, key in enumerate (teams)}
>>> {' 49ers ': 1, ' Ravens ': 2, ' Patriots ': 3, ' Packers ': 0}

10. Initialize the value of the list

Copy Code code as follows:

Items = [0]*3
Print items
>>> [0,0,0]

11. Convert a list to a string

Copy Code code as follows:

Teams = ["Packers", "49ers", "Ravens", "patriots"]
Print ",". Join (teams)
>>> ' Packers, 49ers, Ravens, Patriots '

12. Get the elements from the dictionary

Do not use the following methods

data = {' user ': 1, ' name ': ' Max ', ' Three ': 4}
Try
Except Keyerror:
Replaced by

Copy Code code as follows:

data = {' user ': 1, ' name ': ' Max ', ' Three ': 4}

13. Get the child list

Copy Code code as follows:

x = [1,2,3,4,5,6]
#前3个
Print X[:3]
>>> [1,2,3]
#中间4个
Print X[1:5]
>>> [2,3,4,5]
#最后3个
Print X[-3:]
>>> [4,5,6]
#奇数项
Print X[::2]
>>> [1,3,5]
#偶数项
Print X[1::2]
>>> [2,4,6]

14.6 characters to solve Fizzbuzz

Some time ago Jeff Atwood promoted a simple programming exercise called Fizzbuzz, citing the following questions:

Write a program that prints numbers 1 to 100, multiples of 3, prints "fizz" to replace this number, 5 multiples print "Buzz", and Prints "fizzbuzz" for numbers that are multiples of 3 and 5.
Here's a quick way to solve this problem:

For x in range (:p rint "Fizz" [x%3*4::]+ "Buzz" [X%5*4::]or X

15. Collection

Use the Counter Library

Copy Code code 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's a library called Itertools.

Copy Code code as follows:

From Itertools import combinations
Teams = ["Packers", "49ers", "Ravens", "patriots"]
For game in combinations (teams, 2):
Print game
>>> (' Packers ', ' 49ers ')
>>> (' Packers ', ' Ravens ')
>>> (' Packers ', ' patriots ')
>>> (' 49ers ', ' Ravens ')
>>> (' 49ers ', ' patriots ')
>>> (' Ravens ', ' patriots ')

17.False = = True

In Python, true and false are global variables, so:

Copy Code code as follows:

False = True
If False:
Print "Hello"
Else
Print "World"
>>> Hello

The above is a personal summary of some common Pyton tips, more suitable for beginners, I hope you can enjoy.

Related Keywords:
Related Article

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

## A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

• #### Sales Support

1 on 1 presale consultation

• #### After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

• Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.