This page was generated from `source/notebooks/L1/2_operators.ipynb`_.

Operators and comparisons

Most operators and comparisons in Python work as one would expect:

• Arithmetic operators +, -, *, /, // (integer division), ’**’ power

1 + 2, 1 - 2, 1 * 2, 2 / 2

(3, -1, 2, 1.0)

1.0 + 2.0, 1.0 - 2.0, 1.0 * 2.0, 1.0 / 2.0

(3.0, -1.0, 2.0, 0.5)

# Integer division of float numbers
3.0 // 2.0

1.0

# Note! The power operators in python isn't ^, but **
2 ** 3

8

Note: Division

The / operator always performs a floating point division in Python 3.x. This is not true in Python 2.x, where the result of / is always an integer if the operands are integers. To be more specific, 1/2 = 0.5 (float) in Python 3.x, and 1/2 = 0 (int) in Python 2.x (but 1.0/2 = 0.5 in Python 2.x).

The boolean operators are spelled out as the words and, not, or.

True and False

False

not False

True

True or False

True

Comparison operators >, <, >= (greater or equal), <= (less or equal), == equality, is identical.

2 > 1, 2 < 1

(True, False)

2 > 2, 2 < 2

(False, False)

2 >= 2, 2 <= 2

(True, True)

# equality
[1,2] == [1,2]

True

# objects identical?
l1 = l2 = [1,2]

l1 is l2

True