This course will become read-only in the near future. Tell us at community.p2pu.org if that is a problem.
With Python, learning to program is easy and fun! Many Python programs are clear and concise, reading like plain English. This course will cover the fundamental aspects of Python including data types, flow control, encapsulation, inheritance, and helpful tools from the Python standard library.
Lets look at three components of many programming languages.
Three primary tools we will be working with are:
These three aspects are fundamental to programming in general and will be explored throughout this course.
Examples:
In Python, statements can take many forms and work with many programming elements such as names and operators.
Names are labels that point to a specific item in the computer's memory. Assignment statements are statements where we assign a name to a value, or memory location. Below, a_name points to the memory location of a_value.
>>> a_name = 'a_value'
Names, technically called identifiers, must start with an underscore (the "_" character) or a letter. Names can contain any sequence of letters, numbers, and underscores. Names cannot contain spaces or other special characters. Names are case sensetive, so 'Sunshine' and 'SUNSHINE' are two different names.
There are 33 reserved words that may not be used as names. The following table outlines Python's reserved words.
| False | None | True | and | assert |
| break | class | continue | def | del |
| else | except | finally | for | from |
| global | import | in | is | lambda |
| nonlocal | not | pass | raise | return |
| try | while | with | ||
Expressions typically return some result. The result can then be assigned a name.
In the following example, the expression on the right hand side will be evaluated and then assigned to the name to the left of the '=' assignment operator.
>>> total = 35.9 + 24.29 >>> total 60.19
Basic examples of expressions include arithmetic operations. Operators are included in expressions and consist of symbols such as:
| + | - | / | * | ** |
Here are some operators in action:
>>> 2 + 3 # Addition 5 >>> 3 - 2 # Subtraction 1 >>> 5 * 5 # Multiplication 25 >>> 10 / 5 # Division 2 >>> 3 ** 3 # Exponent 27
If you have any questions or difficulties post them here and we will work together to make sure that everyone has a positive learning experience. Please also post ideas and insights into these concepts. We can learn a lot from each others' perspectives and experience :-)
I wrote a script to address all of the parts of the chapter 2 exercises. I tried to show different ways of doing each thing, so there is no consistency in the script, but there are a lot of different approaches toward the same end instead.
http://dpaste.com/1689144/
Here's my paste for ex 2.2 and 2.3 http://pastebin.com/NxWcy0Dc
Hello Sofiastella,
I've first had assumed your 2.2 was not correct as the print didn't have any space betweens "Hello" and name. But, I've learnt a new thing in python!! Thanks! It seems that when printing multiple variables they are not "added" one after other, but they are space-separated.
So, if we have:
saludation = "Hello"
name = "Sofiastella"
print saludation, name
is not the same that
print saludation + name
which was what I had thought your statement was doing at the beginning.
I've been trying to make exercise 2.2 work for a while this morning, but I keep getting a syntax error. Something's amiss but I don't understand what's wrong. I used the same syntax as in the video.
It looks like this:
name = raw_input("Enter your name: ")
print = "Hello", name
'name' being the name of the variable (he uses something like lmnop but I don't think that's what makes the difference).
As Coffe Bean said, you are not going to see an output because you are doing an "invisible" assignment of the "Hello", name to a variable called print. The print command is designed to make variable contents visible, as in
name = "Bob"
print "Hello", name
Actually, Coffe Bean is forgeting just one thing to make this work:
For Python 3
print("name:%s" % name) # %s is saying that name has to be formated as a string
*Note, if I'm not wrong, in python3 this is suggested to use the format function instead as:
print("name:{0}".format(name)) or
print("name: {name}".format(name=name))
For Python 2
print "name: %s" % name # same than before, the %s tells that name needs to be formated as a string.
Here's my code
Had hard time finding the working link to the textbook with the exercises. Thanks to e.mccormick who shared it earlier: http://www.pythonlearn.com/
Thanks to both of you for the connection to a data version of the excellent Think Python book. Switching away from the math base makes some kinds of understanding easier, I think.
Well, in my case, as my math base is genuinely basic, I, on the contrary, feel an urge to learn more about it.
Link to learning resources not working for me. No error just a blank page!
Here's the code.
The file is in ipython3 which, IMHO, is a great platform for learning python3.
great, here are my exercises: http://dpaste.com/hold/1013198/
Here are my answers: http://dpaste.com/hold/910826/
(the link button is not working, sorry)
