A very simple Python program

vegaseat 2 Tallied Votes 3K Views Share

This is a test to get the Python snippets going! For those of you who are scared of snakes, the language is named after the TV program, not the snake. Python is an interpreted language, but programs to compile/combine the code to an exe file are available (Py2Exe). The latest version of Python can be downloaded for free from the http://www.python.org site.
If you are just starting with the fun of Python coding, direct your eyes to: http://www.daniweb.com/techtalkforums/thread20774.html
If you really want to see what Python can do, take a look at: http://vpython.org/

# a selection of simple Python code to give you a taste of the language ...
#
# Just a few notes about Python:
# Python has a very efficient built-in memory manager.
# Python does not need variable types declared, it is smart enough to figure that out!
# Python uses whitespaces to group statements, this avoids the begin/ends and {}
#   of other languages.  Let's face it, you use whitespaces anyway in these 
#   languages to make the code more readable!  In other words, Python forces you 
#   to make code more readable.  You get used to the indentations naturally.
#   Use the number of spaces you like, the de facto standard is four spaces.
#   Important caveat: 
#     keep the spacing uniform for the group of statements
#     that belong together, and don't mix tabs and spaces.  Avoid tabs!
#
# I used  Python-2.3.4.exe  (the Windows installer package for Python23) 
# from http://www.python.org/2.3.4/ 
# code tested with Python23    vegaseat   16jan2005


print "Simple math like 12345679*63 = ", 12345679*63

# print just an empty line
print

# display numbers 0 to 9
# the indentation before print makes it part of the loop
for number in range(10):
    print number

# print also adds a newline, use a comma to prevent the newline
for number in range(10):
    print number,
  
print

# import the math module for the sqrt() function
import math

# a little more complex this time
# \n is the newline character, % starts the format specifier
# Python does have its roots in the C language
# notice how we use the sqrt() function from the math module
# CYA: more specifically, sqrt() is a function in module math
print "\nSquare root of integers 0 to 9 formatted as a float with 4 decimals:"
for value in range(10):
    squareRoot = math.sqrt(value)
    print "sqrt(%d) = %.4f" % (value, squareRoot)
  
# now it gets a bit more hairy
print "\nDisplay integers 0 to 15 formatted to use 6 spaces ..."
print "(plain, zero-padded, hex and octal)"
print "   %s      %s      %s     %s" % ('%6d', '%06d', '%6x', '%6o')
for value in range(16):
    print "%6d    %06d   %6x  %6o" % (value, value, value, value)

print

print "\nA not so typical for loop:"
for food in "spam", "eggs", "cumquats":
    print "I love", food

print

# a short intro to string slicing
# a little cryptic at first blush, but very powerful
# [begin : < end : step]  end is exclusive, step is optional
# defaults are index begin = 0, index end = length, step = 1
animal = "hippopotamus"
print "this is the string    = ", animal
print "length of string      = ", len(animal)
print "exclude first 3 char  = ", animal[3: ]
print "exclude last 4 char   = ", animal[:-4]
print "reverse the string    = ", animal[::-1]

# define/create a function
# the indented lines are part of the function
def convertFahrenheit2Celsius(fahrenheit):
    celcius = 0.555 * (fahrenheit - 32)
    return celcius

print

# and use the function
# (make sure you define/create the function before you call it)
print "A Fahrenheit to Celcius table:"
# range is from -40 to < 220 in steps of 10
for tf in range(-40, 220, 10):
    print "%5.1fF = %5.1fC" % ( tf, convertFahrenheit2Celsius(tf) )

print

print "A limited set:"
# another variation of the for loop
for tf in -40,0,32,98.6:
    print "%5.1fF = %5.1fC" % ( tf, convertFahrenheit2Celsius(tf) )

print

# test boolean results
print "Is 3 > 5? Result =", 3 > 5  # result = False
print "Is 3 < 5? Result =", 3 < 5  # result = True

# optional wait for keypress
raw_input('Press Enter...')
vegaseat 1,735 DaniWeb's Hypocrite Team Colleague

I am using the Windows version and downloaded Python-2.3.4.exe and VPython-2003-10-05.exe then installed them in that order.

vegaseat 1,735 DaniWeb's Hypocrite Team Colleague

A note:
You don't need VPython to get started, it's just candy!

ono 0 Newbie Poster

I want to generate an Indonesian wordlist file from html files such as those downloaded from http://www.kompas.com [national newspaper online]. Further enhancement, the application should be able to display frequency of occurence of each world listed.

Can python do this?

So the spec. of my simple script, possibly:

Html files is provided in one folder.

He should be able to:
1. read each html file from the folder
until all files read
2. for each file read, get words
3. for each word,
store in a wordlist file, if it has not
been stored there yet
[add frequency of occurence
as required]

Output:
1. A wordlist file ordered from a-z
[one word one line]
2. A wordlist file ordered from a-z plus
frequency of occurence

Thank you....

vegaseat 1,735 DaniWeb's Hypocrite Team Colleague

ono,
you better put that in as a regular thread in the Python Forum.

bumsfeld 413 Nearly a Posting Virtuoso

You made Python sound very interestung to me!

Ene Uran 638 Posting Virtuoso

I have played with Python a little and find it refreshing compared to C++. Gone is the long list of header files and references to obscure libraries in the make/batch file for the compiler. Also gone are the "gotchya" memory leaks.

I have to get used to the fact that type declarations are by inference, and there is only one type of string/character object. Another thing to get used to is the indention of statement blocks to replace {} and the semicolons are gone!

Lardmeister 461 Posting Virtuoso

Interesting this Python code. I highlighted the code and pasted it into IDLE editor and it runs fine. I am using Python 2.5.

siusoon 0 Newbie Poster

great thanks..i run in mac os with python 2.6.2 installed. New to python, but a very good start!

Cireyoretihw 0 Newbie Poster

very clear ... i was looking for the pause and you had it ...

i am trying to get use to the lack of ; at end of each line ...

i am getting a good vibe from this language and it ranks high on the 43 i know

i am getting back into program from past OO coding i was looking for the modular2 version of APL but i think this will do just fine as re-tune my skills.

Lardmeister 461 Posting Virtuoso
# hard to believe that Python23 was 8 years ago!

# ran the old Python23 code through the 2to3.py utility
# just to show the changes in Python syntax for Python3

print("Simple math like 12345679*63 = ", 12345679*63)

# print just an empty line (use '' to potentially work with Python27)
print('')

# display numbers 0 to 9
# the indentation before print makes it part of the loop
for number in range(10):
    print(number)

# print also adds a newline, use a comma to prevent the newline
# in Python3 use end=' '
for number in range(10):
    print(number, end=' ')

print('')

# import the math module for the sqrt() function
import math

# a little more complex this time
# \n is the newline character, % starts the format specifier
# Python does have its roots in the C language
# notice how we use the sqrt() function from the math module
# CYA: more specifically, sqrt() is a function in module math
print("\nSquare root of integers 0 to 9 formatted as a float with 4 decimals:")
for value in range(10):
    squareRoot = math.sqrt(value)
    print("sqrt(%d) = %.4f" % (value, squareRoot))

# now it gets a bit more hairy
print("\nDisplay integers 0 to 15 formatted to use 6 spaces ...")
print("(plain, zero-padded, hex and octal)")
print("   %s      %s      %s     %s" % ('%6d', '%06d', '%6x', '%6o'))
for value in range(16):
    print("%6d    %06d   %6x  %6o" % (value, value, value, value))

print('')

print("\nA not so typical for loop:")
for food in "spam", "eggs", "cumquats":
    print("I love", food)

print('')

# a short intro to string slicing
# a little cryptic at first blush, but very powerful
# [begin : < end : step]  end is exclusive, step is optional
# defaults are index begin = 0, index end = length, step = 1
animal = "hippopotamus"
print("this is the string    = ", animal)
print("length of string      = ", len(animal))
print("exclude first 3 char  = ", animal[3: ])
print("exclude last 4 char   = ", animal[:-4])
print("reverse the string    = ", animal[::-1])

# define/create a function
# the indented lines are part of the function
def convertFahrenheit2Celsius(fahrenheit):
    celcius = 0.555 * (fahrenheit - 32)
    return celcius

print('')

# and use the function
# (make sure you define/create the function before you call it)
print("A Fahrenheit to Celcius table:")
# range is from -40 to < 220 in steps of 10
for tf in range(-40, 220, 10):
    print("%5.1fF = %5.1fC" % ( tf, convertFahrenheit2Celsius(tf) ))

print('')

print("A limited set:")
# another variation of the for loop
for tf in -40,0,32,98.6:
    print("%5.1fF = %5.1fC" % ( tf, convertFahrenheit2Celsius(tf) ))

print('')

# test boolean results
print("Is 3 > 5? Result =", 3 > 5)  # result = False
print("Is 3 < 5? Result =", 3 < 5)  # result = True

# optional wait for keypress
input('Press Enter...')
vegaseat 1,735 DaniWeb's Hypocrite Team Colleague

Thanks Ludwik! It needed to be updated after 8 years.

sthompson411 0 Newbie Poster

I have been a cobol programmer for decades (too many)! But now I want to learn Python. I am a beginner in Python programming. I know how I would approach the following in cobol, but not in Python. Please advise on how I am to approach the following.
Count the number of occurrences of each word in a resume, with the elimination of commas.
Thank you.

vegaseat 1,735 DaniWeb's Hypocrite Team Colleague
vegaseat 1,735 DaniWeb's Hypocrite Team Colleague

Wow, my first exploration of Python! Now I am studying Apple's Swift language that has a lot of Python ideas in it.

My first exploration of Swift is here ...
https://www.daniweb.com/software-development/computer-science/code/496606/a-taste-of-swift-part-1

Swift is being developed by Apple as a safe (weeds out errors early) and friendly language to write applications for iMac (OS X), and iPad, iPod, iPhone, iWatch (iOS). It works well in combination with Apple's Xcode IDE. A release for the Linux OS is expected later this year. You can test drive Swift code on Windows OS using the playground at
http://swiftstub.com

Also note that the present version of Swift is 1.2, but Swift version 2 is out in beta and has made a number of positive changes to the syntax and also added improved error handling. Python went through that with the Python2 to Python3 changes.

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