Basic Python Tutorial Lesson Two

# How data types work

# If you give the computer numbers with decimals, you’ll see an error when it tries to add them.
# To avoid this, we can tell the computer to treat them as floats.

num_1 = input("Give me a number: ")
num_2 = input("Give me a second number: ")

print("At the moment, I am treating them as strings.")
print(num_1, "+", num_2, "=", num_1 + num_2)

print("But if I treat them as floats, I get this")
print(num_1, "+", num_2, "=", float(num_1) + float(num_2))

# Here, “float(num_1)” tells the computer to treat the contents of num_1 as
# a floating point number. Of course, if we didn’t enter a number when we 
# were asked, we’ll get an error!
#
###########################################
#An example of a error in the Python Shell#
###########################################
#
# >>>
# >>>
# Give me a number: I have no idea
# Give me a second number: what to do
# At the moment, I am treating them as strings.
# I have no idea + what to do = I have no idea what to do
# But if I treat them as floats, I get this.
###############################################################
# Traceback (most recent call last):                          #
# File"/root/my-documents/Py/float.py",line11, in <module>    #
#   print("num_1+num_2, "=" float(num_1) + float(num_2))      #
#ValueError: could not convert string to float: I have no idea#
# >>>                                                         #
###############################################################
#
################
#End Of Example#
################
#
#   The computer tries to convert the string of letters into a number, 
#   but of course it can’t, so there’s an error.
#
#   Just for the sake of it, here’s what happens if we enter integers, 
#   but get the computer to treat them as floats (don’t worry, this won’t cause an error).
#
#
#
######################
#Python Shell Example#
######################
#
# >>>
# >>>
# Give me a number:67
# Give me a number:31
# At the moment, I am treating them as strings.
# 67 + 31 = 6731
# But if I treat them as floats, I get this.
# 67 + 31 = 98.0
# >>>
#
################
#End Of Example#
################
#
#
# The computer is quite happy to convert these numbers into floats, 
# the answer is “98.0″ which shows that we are working with floating point numbers.
#
#
# Before we leave this topic, I will show you what happens if you use 
# multiplication on strings. (You won’t be surprised to hear that you can’t divide or subtract strings!).
#
# 
#
######################
#Python Shell Example#
######################
#
# >>>
# >>>
# Give me a number:7
# At the moment I am treating it as a string.
# 7 times 5  = 77777
# But if I treat it as a float i get this.
# 7 times 5 = 35.0
# >>>
#
################
#End Of Example#
################
#
# As a wise person once said, a computer does what you tell it to 
# do, not what you want it to do!
# Happy Coding, Mr Hogg
#
#

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