To begin learning python, download python here.
Install it as per the directions given in the above link.
Then go the folder where python is installed and double-click python.exe to start the python shell.
In the shell that opens, type the first command as print ("Hello World") and see the output as follows:
Congratulations!
Python is up and running and your first python line has just been executed.
Some more code to whet your appetite:
Example 1: Creating a list
foo = [] # declares 'foo' as a list
foo.append(1) # add an integer variable
foo.append("Hello"); # add a string in quotes
foo.append('World'); # add another string but in single quotes
foo.append(2.0); # add a floating point number
# iterate over the list and print the elements.
for v in foo:
print (v) # note the indentation before print statement!
# Python provides several function for easy list manipulation:
>>> l = [4, 1, 7, 2, 9]
>>> l
[4, 1, 7, 2, 9]
>>> sorted(l)
[1, 2, 4, 7, 9]
>>> l
[4, 1, 7, 2, 9]
# sorted() does not change the input list argument.
# If that is desired, use list.sort
>>> l.sort()
>>> l
[1, 2, 4, 7, 9]
# Reversing a list is easy!
>>> list(reversed(l))
[9, 7, 4, 2, 1]
>>> l.reverse()
>>> l
[9, 7, 4, 2, 1]
Output:
1
Hello
World
2.0
Example 2: Tuples (immutable structures)
tple = (1,2,3); # a tuple is created using round brackets.
print (tple[1]); # prints 2
a,b,c,d = tple; # assigns values from the tuple one by one.
tple[1] = 5; # tuples are immutable!
# Traceback (most recent call last):
# TypeError: 'tuple' object does not support item assignment
Note: Tuples are similar to those in Erlang
except that tuples in Erlang use curly braces and are mutable.
Example 3: Operators and string conversion
print (
"hello "*2 + "world" + # strings can be multiplied by numbers and added by + operator
"\n" + # \n is used for newline
str(1 + 2 * 6 / 2) + # all normal operators like + - * /
"\n" + # Use str () to convert to string
str ((3**2) % 5) # ** is for power and % is for remainder.
)
print ( [1,2,3]*2 + [0,0] ) # lists can also be multiplied with numbers and added like strings
Output:
hello hello world
7.0
4
[1, 2, 3, 1, 2, 3, 0, 0]
Got a thought to share or found a bug in the code? We'd love to hear from you: