# Python snippets

From http://interactivepython.org, follows snippets (very short bits of code you do as try outs)

## Contents |

# Hello World

#--------------------------------------------------- # This demo program shows off how elegant Python is! # Written by Joe Soap, December 2010. # Anyone may freely copy or modify this program. #--------------------------------------------------- print("Hello, World!") # Isn't this easy!

(this should work with Syntax Highlighting)

## "Oh no", she exclaimed, "Ben's bike is broken!"

print('''"Oh no", she exclaimed, "Ben's bike is broken!"''')

## This message will span several lines of text

message = """This message will span several lines.""" print(message) print("""This message will span several lines of the text.""")

# If you are not sure what class a value falls into,

Python has a function called **type** which can tell you.

print(type("Hello, World!")) print(type(17)) print("Hello, World")

# Variables

message = "What's up, Doc?" n = 17 pi = 3.14159 print(message) print(n) print(pi)

## How many ?

minutes = 645 hours = minutes / 60 print(hours)

## This / and that //

In the previous example, what we might have wanted to know was how many whole hours there are, and how many minutes remain. Python gives us two different flavors of the division operator. The second, called integer division, uses the token //. It always truncates its result down to the next smallest integer (to the left on the number line).

print(7 / 4) print(7 // 4) minutes = 645 hours = minutes // 60 print(hours)

### Actual output in hours and minutes

#!/usr/bin/env python minutes = 645 # Variable 1: total number of minutes hours = minutes // 60 # variable 2 uses a // division, takes the smaller integer. rem=(minutes-(hours*60)) # variable 3 gathers how many minutes where left out print((minutes),("minutes"),("make"),(hours),("hours"),("and"),(rem),("minutes")) # result in -h format

### Both ways, the Math Way and the Py way

#!/usr/bin/env python # Define some Variables: m = 1645 h = m // 60 d = h // 24 # The math Way: rm = (m-(h*60)) #The Py Way: rp = m % 60 print((m),("min"),("="),(d),("d."),(h),(":"),(rm),("with maths.")) print((m),("min"),("="),(d),("d."),(h),(":"),(rp),("with py."))

Nicer Output:

#!/usr/bin/env python # An hour/minutes counter, since you cant divide 1645 by 60 and have # a meaningful answer. # Define some Variables: m = 1645 h = m // 60 d = h // 24 # 1645 doesn't divide by 60, how do we get the right answer: # some more variables; there are here 2 ways of doing that: # The math Way: rm = (m-(h*60)) #The Py Way: rp = m % 60 print() print((" How much"),(m),("minutes make in days, hours, minutes?")) print() print((" "),(d),("d"),(h),("h"),(rm),("m"),("with maths.")) print((" "),(d),("d"),(h),("h"),(rp),("m"),("with py.")) print() # Easy no ?

Outputs in:

[jph@1215s bin]$ python pstuff.py How much 1645 minutes make in days, hours, minutes? 1 d 27 h 25 m with maths. 1 d 27 h 25 m with py.

# Get Some Input

Same, with input at the prompt AND lots unnecessary variables: one can just define by 24 or 60, no need to first define the 24 factor, much less to pass it as an integer as a new factor...

#!/usr/bin/env python # # An hour/minutes calculator, taking input from the prompt. # Define the Input Variable:minutes_from_input = input("Enter how many minutes: ")# At this stage, the input is just a string, can't do anything with it! # One MUST convert it to an integer to perform maths on:minutes = int(minutes_from_input)# Following not necessary, actually snobbish:factorhourday = 24factorhourminute = 60factordh= int(factorhourday)factorhm = int(factorhourminute)# Variables declarations and some basic maths:hours = minutes // factorhmdays = hours // factordh#Let's solve the problem! # The math Way:hours_remain_in_math = (hours-(days*24))minutes_remain_in_math = (minutes-(hours*60))#The Py Way:hours_remain_with_py = hours % 24minutes_remain_with_py = minutes % 60# And get the answer out there.print()print((" How much"),(minutes),("minutes make in days, hours, minutes?")) print() print((" "),(days),("d"),(hours_remain_in_math),("h"),(minutes_remain_in_math),("m"),("with maths.")) print((" "),(days),("d"),(hours_remain_with_py),("h"),(minutes_remain_with_py),("m"),("with py.")) print()

Outputs in:

[jph@1215s bin]$ python pstuff.py Enter how many minutes: 12745 How much 12745 minutes make in days, hours, minutes? 8 d 20 h 25 m with maths. 8 d 20 h 25 m with py. [jph@1215s bin]$

## More clockwork

Derived, refined from *You look at the clock and it is exactly 2pm. You set an alarm to go off in 51 hours. At what time does the alarm go off?*

now = input("What time, rouned in hours, is it? ") nowint =int(now) test = input("how many hours to wake-up? ") testint = int(test) ipt = testint % 24 days = testint // 24 time = nowint + ipt res = time % 24 print(("From"),(nowint),("you'll wake up"),(days),("days &"),(ipt),("hours later, at"),(res),("hopefully."))

## Interest compound calculator

http://en.wikipedia.org/wiki/Compound_interest

pi = input ("How much money Sir? ") p = int(pi) n = 12 ri = input ("Interest rate as given to you by the bank Sir? ") rm = float(ri) r = (rm/100) ti = input("How many years Sir? ") t = int(ti) Am = p*((1+(r/n))**(n*t)) Ar = Am * 100 Ad = Ar // 1 A = Ad /100 print(p) print(r) print(A)

## Radius in any metrics you'd like

Write a program that will compute the area of a circle. Prompt the user to enter the radius and print a nice message back to the user with the answer.

ri=input("Radius? ") u=input("Units?") r=float(ri) pi=3.14159 print(("your disc has a surface of"),pi*(r**2),(u))

## C / F

Write a program that will convert degrees celsius to degrees fahrenheit.

# [°F] = [°C] × 9⁄5 + 32 # [°C] = ([°F] − 32)× 5⁄9 ci=input("your input in Celsius (leave blank if Farehneit)") fi=input("Your input in Farenheit (Leave blank if Celsius)") c=float(ci) f=float(fi) rf=((c*9/5)+32) rtc=((f-32)*5/9) #rounding up the C results to 2 decimal paces max. r100=rtc*100 rdec=r100//1 rc=rdec/100 print((c),("C"),("makes:"),(rf),("F")) print((f),("F"),("makes:"),(rc),("C"))

# Modules

## Meet Miss Turtle

#!/usr/bin/env python import turtle wn = turtle.Screen() wnbgi=input('''Choose screen color; among acknowledged values are: -aqua, blue, navy, teal, -black, gray, silver, white, -fuchsia, -green, lime, olive, maroon, -orange, -purple, -red, -yellow''') wn.bgcolor(wnbgi) tpi=input("pensize, in integer, please") ps=int(tpi) tess = turtle.Turtle() tess.color("blue") # make tess blue tess.pensize(ps) # set the width of her pen tess.forward(50) tess.left(120) tess.forward(50) wn.exitonclick()

# Statement "for"

## For the Spiral

#!/usr/bin/python # for w/ spiral import turtle wn = turtle.Screen() alex = turtle.Turtle() alex.pensize(3) ls=50 for i in [0,1,2,3,4,6,7,8,9,10,11,12]: alex.left(90) alex.forward(ls) ls=ls+25 wn.exitonclick()

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**Python snippets**