Python

Installing python

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]

1
Hello
World
2.0

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

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

hello hello world
7.0
4

[1, 2, 3, 1, 2, 3, 0, 0]