Page 95 - Programming With Python 3

An Introduction to STEM Programming with Python — 2019-09-03a Page 82
Chapter 7 — In, If, Random, and While

"b" in {'a':9, 'b':3} — is true ('b' is a key)
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"x" in {'a':9, 'b':3} — is false ('x' is not a key)
9 in {'a':9, 'b':3} — is false (9 is not a key, it is a value)

value in sequence Operator
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Returns true if the value is found in a sequence or other iterable object. For
dictionaries tests if the value is a key.

https://docs.python.org/3/reference/expressions.html#membership-test-operations
http://bit.ly/2Qv9q4E

Edition

Try this code with several state abbreviations that you know.

1| states = {"AL":"ALABAMA", "AK":"ALASKA", "AZ":"ARIZONA",
"AR":"ARKANSAS", "CA":"CALIFORNIA ", "CO":"COLORADO",
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"CT":"CONNECTICUT" }
2| code = input("Enter State Code").upper()
3| print(code, "exists in dictionary:", code in states)
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Random Numbers and Shuffle

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To play an game or do a simulation we need a source of random numbers. A random number is a
number that is selected from a range or group of numbers that has no apparent correlation to the
2
previous numbers or future numbers selected. You can think of a random number generated by Python
to be like throwing a coin or dice, you just don't know what will happen next.

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Importing the Random Module

To use random numbers in your programs you will need to include the following line of code BEFORE
you want to use a random number method. It is recommended that your import statements, of which we
will show a few more in this introduction, be included in the beginning of your program.
Edition
1| import random

2 http://mathworld.wolfram.com/RandomNumber.html
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