: https://www.edx.org/course/mit/6-00-1x/introduction-computer-science/1122 
Topic: Programming in Python (Read 2698 times)
I found another course but this one use a real interpreter : https://www.edx.org/course/mit/6-00-1x/introduction-computer-science/1122
: https://www.edx.org/course/mit/6-00-1x/introduction-computer-science/1122 Traceback (most recent call last):
File "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
intFile "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
str
Fix
Quote
print str(miles_input) + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
It's already been done.
I've started the course once again.
Traceback (most recent call last):
File "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
intFile "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
str
Fix
Quote
print str(miles_input) + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
There was a thread on this forum with different things people created with python.
I need to learn python
Jump aboard with this course! I'm pretty much a beginner so we can assist one another via this thread
I'm dedicating 1-2 hours a day to this, just need to make it habit for it to stick in my mind otherwise I'll forget.Will do. Coursera seems to have other awesome courses too.
So, unless you want to draw erroneous conclusions about how to program, as has become glaringly obvious in this little episode, I suggest you only test your code using your local python interpreter.
I don't know if this is related but it only uses the libraries we need to complete the course.
I need to learn python
Jump aboard with this course! I'm pretty much a beginner so we can assist one another via this thread
I'm dedicating 1-2 hours a day to this, just need to make it habit for it to stick in my mind otherwise I'll forget.
I need to learn python
I'm pretty sure I know what your problem is. First, what version of Python are you using. Type python at the command prompt.
There is no command prompt. It's a web browser implementation for the course. It works fine with codeskulptor but throw an error with python 2.7.3 on my computer.
Code:
Traceback (most recent call last):
File "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
for the print command, intead of adding a bunch of things together, it might be better to use placeholders?
Code:
print "%f miles = %f km." % (miles_input, miles_to_km_no_float(miles_input))
Yes. Such power using C style printf printing. Read up on formatting for printf.
hero member
Activity: 756
Merit: 500
It's all fun and games until somebody loses an eye
I'm pretty sure I know what your problem is. First, what version of Python are you using. Type python at the command prompt.
There is no command prompt. It's a web browser implementation for the course. It works fine with codeskulptor but throw an error with python 2.7.3 on my computer.
Code:
Traceback (most recent call last):
File "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
for the print command, intead of adding a bunch of things together, it might be better to use placeholders?
Code:
print "%f miles = %f km." % (miles_input, miles_to_km_no_float(miles_input))
Code:
def miles_to_km(miles):
return miles * 1.60934
miles_input = input('Please input miles to convert in km: ')
print miles_to_km(float(miles_input))
What's likely happening here is that when querying for input, you're getting a string. What you want is a number. You don't know if the string, when converted to a number, has a decimal place or not, so you take the safe route and convert it to a float. But this is all about preparing the arguments for the function.
The function should expect a number (int or float) and receive that.
Even further proof: here we're guaranteeing that we're passing an integer into the function:
Code:
def miles_to_km(miles):
return miles * 1.60934
print miles_to_km(int(1))
Yes, I know this is how I did it the first time but it doesn't works using input() in the online version.
Even further proof: here we're guaranteeing that we're passing an integer into the function:
Code:
def miles_to_km(miles):
return miles * 1.60934
print miles_to_km(int(1))
So, unless you want to draw erroneous conclusions about how to program, as has become glaringly obvious in this little episode, I suggest you only test your code using your local python interpreter.
I will; however, the online interpreter is the only way to submit our work for the course.
Even so, the function was not the problem. Run this online:
Code:
def miles_to_km(miles):
return miles * 1.60934
print miles_to_km(1)
So, unless you want to draw erroneous conclusions about how to program, as has become glaringly obvious in this little episode, I suggest you only test your code using your local python interpreter.
I will; however, the online interpreter is the only way to submit our work for the course.
So, unless you want to draw erroneous conclusions about how to program, as has become glaringly obvious in this little episode, I suggest you only test your code using your local python interpreter.
Whatever the case, you don't need to convert your integer to a float in the function, because multiplying it by a float already does that.
Also, I can't get a program to print the Python version to work in the online version.
For example, this does not work:
import platform
print(platform.python_version())
Also, I can't get a program to print the Python version to work in the online version.
For example, this does not work:
import platform
print(platform.python_version())
I think it's an incomplete version 2.
Whatever the case, you don't need to convert your integer to a float in the function, because multiplying it by a float already does that.
Also, I can't get a program to print the Python version to work in the online version.
For example, this does not work:
import platform
print(platform.python_version())
Also, I can't get a program to print the Python version to work in the online version.
For example, this does not work:
import platform
print(platform.python_version())
And that's the problem. Your toy Python interpreter did not catch the problem.
I know it's meant to make it easy for student to share the link for their homework but the python implementation lack some feature.
The problem is not with the functions. This is pointless:
Code:
def miles_to_km_with_float(miles):
return float(miles) * 1.60934
Everything I said is correct.
You're writing bad code. Here is a fixed version of your code:
You're writing bad code. Here is a fixed version of your code:
Code:
def miles_to_km_no_float(miles):
return miles * 1.60934
def miles_to_km_with_float(miles):
return float(miles) * 1.60934
miles_input=input('Please input miles to convert in km:')
print str(miles_input) + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
print str(miles_input) + " miles = " + str(miles_to_km_with_float(miles_input)) + " km (float)"
It works fine using python on my computer but still get the same old result with codeskulptor.
And that's the problem. Your toy Python interpreter did not catch the problem.
I'm pretty sure I know what your problem is. First, what version of Python are you using. Type python at the command prompt.
There is no command prompt. It's a web browser implementation for the course. It works fine with codeskulptor but throw an error with python 2.7.3 on my computer.
Code:
Traceback (most recent call last):
File "test.py", line 13, in
print miles_input + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
TypeError: unsupported operand type(s) for +: 'int' and 'str'
Everything I said is correct.
You're writing bad code. Here is a fixed version of your code:
You're writing bad code. Here is a fixed version of your code:
Code:
def miles_to_km_no_float(miles):
return miles * 1.60934
def miles_to_km_with_float(miles):
return float(miles) * 1.60934
miles_input=input('Please input miles to convert in km:')
print str(miles_input) + " miles = " + str(miles_to_km_no_float(miles_input)) + " km (no float)"
print str(miles_input) + " miles = " + str(miles_to_km_with_float(miles_input)) + " km (float)"
I'm pretty sure I know what your problem is. First, what version of Python are you using. Type python at the command prompt.
An integer multiplied by a float returns a float. Since 1.60934 is a float, even if miles is an integer, the result will be a float.
If miles == 1 with this code:
Code:
def miles_to_km(miles):
return miles * 1.60934
The answer is "11"
If use this line:
Code:
def miles_to_km(miles):
return float(miles) * 1.60934
The answer is correct.
This program prints 1.60934.
Code:
def miles_to_km(miles):
return miles * 1.60934
print miles_to_km(1)
Show me your entire program here.
http://www.codeskulptor.org/#user19_9Zu5nZ2ctm_3.py
I think it's because that I convert a string to a float. It is not integer --> float.
An integer multiplied by a float returns a float. Since 1.60934 is a float, even if miles is an integer, the result will be a float.
If miles == 1 with this code:
Code:
def miles_to_km(miles):
return miles * 1.60934
The answer is "11"
If use this line:
Code:
def miles_to_km(miles):
return float(miles) * 1.60934
The answer is correct.
This program prints 1.60934.
Code:
def miles_to_km(miles):
return miles * 1.60934
print miles_to_km(1)
Show me your entire program here.
An integer multiplied by a float returns a float. Since 1.60934 is a float, even if miles is an integer, the result will be a float.
If miles == 1 with this code:
Code:
def miles_to_km(miles):
return miles * 1.60934
It prints "11"
If use this line:
Code:
def miles_to_km(miles):
return float(miles) * 1.60934
The answer is correct.
An integer multiplied by a float returns a float. Since 1.60934 is a float, even if miles is an integer, the result will be a float.
Nice
Edit:
Improved version that assumes that the user only input numbers:
Code:
def miles_to_km(miles):
return miles * 1.60934
def km_to_miles(km):
return km / 1.60934
print miles_to_km(10)
print km_to_miles(16.0934)
Edit:
Improved version that assumes that the user only input numbers:
Code:
def miles_to_km(miles):
return float(miles) * 1.60934
def km_to_miles(km):
return float(km) / 1.60934
miles_input = input('Please input miles to convert in km:')
print miles_input + " miles = " + str(miles_to_km(miles_input)) + " km"
km_input = input('Please input km to convert in miles:')
print km_input + " km = " + str(km_to_miles(km_input)) + " miles"
Working on the functions lesson at the moment, I didn't really understand it at first. I think I've got it now as I tried to write some of my own and it outputs the correct answer. Maybe someone can check that my thinking is right on these functions I wrote.
Quote
# converts cm to inches
def cm_to_inches(cm):
inch = 1 / 2.54 * cm
return inch
a1 = cm_to_inches(25.4)
print a1
def cm_to_inches(cm):
inch = 1 / 2.54 * cm
return inch
a1 = cm_to_inches(25.4)
print a1
Less lines are better when it doesn't reduce clarity. The reason is it allows more lines visible on the screen, which allows greater comprehension while examining the code. But don't sacrifice white space to achieve that.
Quote
def cm_to_inches(cm):
return cm / 2.54
return cm / 2.54
And there's no point in dividing by 1 or multiplying by 1 or zero when they are constants:
Quote
# convert inches to cm
def inch_to_cm(inch):
cm = 2.54 / 1 * inch
return cm
def inch_to_cm(inch):
cm = 2.54 / 1 * inch
return cm
Try this:
Quote
def inch_to_cm(inch):
return inch * 2.54
return inch * 2.54
I recommend trying a guide called learn python the hard way.
It is really helpful and easy.
It is really helpful and easy.
Is this about right for creating a function and then creating another which calls the previous function?
http://www.codeskulptor.org/#user19_v3vzRwYgMq_1.py
You can call a function anywhere you want in your code, even inside another function. http://www.codeskulptor.org/#user19_v3vzRwYgMq_1.py
Is this about right for creating a function and then creating another which calls the previous function?
http://www.codeskulptor.org/#user19_v3vzRwYgMq_1.py
http://www.codeskulptor.org/#user19_v3vzRwYgMq_1.py
Yep you got it
Just two remarks: do you know you can "print cm_to_inches(1.0)" directly? And why writing ones in the formulas? Why not just "cm=2.54*inch"?
Just two remarks: do you know you can "print cm_to_inches(1.0)" directly? And why writing ones in the formulas? Why not just "cm=2.54*inch"?
The example used in the course is fahrenheit to celsius but I couldn't seem to grasp it. I tried thinking of a few different ways I might use a function and those are just the things that came to mind. Obviously they are not useful as you've provided better options but for the purposes of understanding how a function operates, it seems to have worked for me
By the way there is a computer networks course starting in 3 months: https://www.coursera.org/course/comnetworks
Quote
Course Syllabus:
Introduction, Protocols and Layering
Physical and Link layers
Retransmissions, Multiple access, Switching
Network layer, Internetworking
Intra- and Inter-domain Routing
Transport layer, Reliability
Congestion Control
DNS, Web/HTTP, Content Distribution
Quality of Service and Real-time Apps
Network Security
Introduction, Protocols and Layering
Physical and Link layers
Retransmissions, Multiple access, Switching
Network layer, Internetworking
Intra- and Inter-domain Routing
Transport layer, Reliability
Congestion Control
DNS, Web/HTTP, Content Distribution
Quality of Service and Real-time Apps
Network Security
do you know you can "print cm_to_inches(1.0)" directly?
You are right but he did it the way it is taught in the video. I guess it is easier for beginner to understand.
You can share your code with CodeSkulpor for easier review: http://www.codeskulptor.org/#user19_HWWqVRQDa8_0.py
I don't know the exact formula but the code looks good to me.
I just finished everything for this week.
I don't know the exact formula but the code looks good to me.
I just finished everything for this week.
Yep you got it
Just two remarks: do you know you can "print cm_to_inches(1.0)" directly? And why writing ones in the formulas? Why not just "cm=2.54*inch"?
Just two remarks: do you know you can "print cm_to_inches(1.0)" directly? And why writing ones in the formulas? Why not just "cm=2.54*inch"?
Working on the functions lesson at the moment, I didn't really understand it at first. I think I've got it now as I tried to write some of my own and it outputs the correct answer. Maybe someone can check that my thinking is right on these functions I wrote.
# converts cm to inches
def cm_to_inches(cm):
inch = 1 / 2.54 * cm
return inch
a1 = cm_to_inches(25.4)
print a1
# convert inches to cm
def inch_to_cm(inch):
cm = 2.54 / 1 * inch
return cm
a2 = inch_to_cm(10)
print a2
# convert 100 to 1 (100 = 1, 500 = 5, 1000 = 10)
def onehundred_to_one(hundred):
one = hundred / 100
return one
a3 = onehundred_to_one(800)
print a3
# convert 1 to 100 (1 = 100, 5 = 500, 10 = 1000)
def one_to_onehundred(one):
hundred = 100 * one
return hundred
a4 = one_to_onehundred(5)
print a4
Quote
# converts cm to inches
def cm_to_inches(cm):
inch = 1 / 2.54 * cm
return inch
a1 = cm_to_inches(25.4)
print a1
# convert inches to cm
def inch_to_cm(inch):
cm = 2.54 / 1 * inch
return cm
a2 = inch_to_cm(10)
print a2
# convert 100 to 1 (100 = 1, 500 = 5, 1000 = 10)
def onehundred_to_one(hundred):
one = hundred / 100
return one
a3 = onehundred_to_one(800)
print a3
# convert 1 to 100 (1 = 100, 5 = 500, 10 = 1000)
def one_to_onehundred(one):
hundred = 100 * one
return hundred
a4 = one_to_onehundred(5)
print a4
New lessons are up.
Python being a Object orientated language is a great start. If you ever do get good enough that you know a lot, then you should also pick up other languages easier too.
Python is a great language, it is a lot quicker to code then any other language out there. It is not too slow compare to C either.
It's very slow compared to C. Sometimes 50 or more times slower. On the other hand, if your whole Python program just does one function call which does some serious number crunching, and that Python function was written in C, then sure, it's not too slow compared to C.
Python speed: http://benchmarksgame.alioth.debian.org/u32/benchmark.php?test=nbody&lang=python3&id=1&data=u32
C speed: http://benchmarksgame.alioth.debian.org/u32/benchmark.php?test=nbody&lang=gcc&id=1&data=u32
Results show C is 50 times faster and uses one tenth the amount of memory.
Do SICP http://mitpress.mit.edu/sicp/
Afterwards you can code in any language, you just need to learn it's syntax which takes a weekend.
Afterwards you can code in any language, you just need to learn it's syntax which takes a weekend.
Incorrect. Oh sure, you're going to learn Lisp, C++, Haskell and Prolog in a weekend just by learning its syntax.
Python is a great language, it is a lot quicker to code then any other language out there. It is not too slow compare to C either.
hero member
Activity: 756
Merit: 500
It's all fun and games until somebody loses an eye
I learned some python a while ago. I found it useful to solve the problems at projecteuler.net using python to experiment with different programming and mathematical techniques.
I took learning a programming language as a hobby and chose python. It has been a great learning experience and really keeps your mind busy.
JackJack has been a great "guidance counselor"
So enjoy your ride...
Still got a lot of learning to do but its "educational entertainment"
JackJack has been a great "guidance counselor"
So enjoy your ride...
Still got a lot of learning to do but its "educational entertainment"
Yeah, if you're looking to do web stuff python probably isn't the most "ideal," BUT python IS a great multi-purpose language. It can be used for so many things, much like C/C++.
Just a reminder that this course has started (week 0). It's pretty straight forward but we can use this thread to assist one another if needed.
Do SICP http://mitpress.mit.edu/sicp/
Afterwards you can code in any language, you just need to learn it's syntax which takes a weekend.
Afterwards you can code in any language, you just need to learn it's syntax which takes a weekend.
Instead of learning python, learn the OOP then you can easily learn any language. I personally think python is a descent web language. I personally like php, and JavaEE for web, and Objective-c for desktop/ios apps.
This is nitpicking, but python is not a "web language". It's multipurpose and one can code desktop programs with it (and wxPython). I did so, some time ago.
I'm now also registered to an initiation course to C++ but it's in french: https://www.coursera.org/course/intro-cpp-fr
I'm already semi-fluent in C++ but only learnt via source code reading and working on small projects. Maybe it will help me to start from the beginning, then there is a part 2 course for more advanced students.
I'm already semi-fluent in C++ but only learnt via source code reading and working on small projects. Maybe it will help me to start from the beginning, then there is a part 2 course for more advanced students.
Thanks for the offer of assistance.
I'll post this over at /r/bitcoin and see if we can get a small group for the 9th next month.
I'll post this over at /r/bitcoin and see if we can get a small group for the 9th next month.
I don't know if this is the ideal language to learn if I want to develop my Bitcoin ideas, perhaps someone can offer some advice in that regard
I learnt Python and Bitcoin by looking/forking this software: https://github.com/joric/pywallet/I think I'm now pretty good at both
I can help you if you need some help
I'm in! I think python is a good multi-purpose language.
Hey,
I've been wanting to learn to program for a while but I never really bothered as I had no idea of what to build and so my motivation was zero. Because of Bitcoin, I have some simple ideas that I'd like to build so now is as good a time as any to learn how to program. To that end, I thought I would share with others a course on python is starting on October 9th titled "An Introduction to Interactive Programming in Python".
https://www.coursera.org/course/interactivepython
I don't know if this is the ideal language to learn if I want to develop my Bitcoin ideas, perhaps someone can offer some advice in that regard but anyway, I thought I would share the link here and see if anyone else was interested in doing this as a group, perhaps we can collaborate and help each other to learn via the forum or on irc in the #interactivepython channel.
Anyone else interested?
I've been wanting to learn to program for a while but I never really bothered as I had no idea of what to build and so my motivation was zero. Because of Bitcoin, I have some simple ideas that I'd like to build so now is as good a time as any to learn how to program. To that end, I thought I would share with others a course on python is starting on October 9th titled "An Introduction to Interactive Programming in Python".
https://www.coursera.org/course/interactivepython
I don't know if this is the ideal language to learn if I want to develop my Bitcoin ideas, perhaps someone can offer some advice in that regard but anyway, I thought I would share the link here and see if anyone else was interested in doing this as a group, perhaps we can collaborate and help each other to learn via the forum or on irc in the #interactivepython channel.
Anyone else interested?
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