I just started with python. My teacher gave me an assignment and I'm stuck on a project where I have to make the numbers of characters appear when someone enters their name for input command input("what is your name") I don't think I have been taught this and google is giving me a hard time when trying to look for the command. This might be Childs play to most but can anyone throw me a tip/hint?
using print(len(myVariable)) should output the number of characteres that the string has. You should familiarize yourself with python methods.
Here are some resources:
https://docs.python.org/3/library/functions.html
https://www.w3schools.com/python/ref_func_len.asp
Printing the length of a variable is very easy with Python due to the many built-in functions you can perform on strings! In this case, you would use use len(). Read about other helpful string methods in python too in order to get a head start on your class!
inputtedName = input("What is your name? ")
nameLength = len(inputtedName)
print("Your name is " + str(nameLength) + " letters.")
print(f"Your name is {nameLength} letters.")
The first print statement uses something called string concatenation to create a readable sentence using variables. The second uses f strings to make using variables in your strings even easier!
This question already has answers here:
How do I reverse a string in Python?
(19 answers)
Closed 9 years ago.
I am new to programming. I am trying to write a code to print the reverse of any given string.
I have written the following code:
import math
string= raw_input ("Enter string")
n= len(string)
ol= n-1
for ol>-1,ol--:
print string[ol]
but i am getting syntax error. Please help me to figure this out.
Python tries very hard to present code in a readable way. This means you don't get many of the ugly, hard to understand shortcuts that other languages like C offer. Instead, you get other, much easier to understand shortcuts.
The code to loop over a range in python is:
for ol in range(n):
To iterate backwards, use
for ol in range(n-1,-1,-1):
But of course, someone couldn't resist and add an unreadable shortcut to the language:
print string[::-1]
Related:
Loop backwards using indices in Python?
Reverse a string in Python
You can use these links for your further work, i know that this answer is out of the topic:
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If you want to code the string reverse yourself, try this as well. This will be useful when you reverse a very large string. You just have to traverse only half of it.
Data = list("ABCDEF")
Len = len(Data)
for i in range(Len//2):
Data[i], Data[Len - i - 1] = Data[Len - i - 1], Data[i]
Data = ''.join(Data)
print Data
NOTE: This solution is just for learning. For practical purposes, use #Aaron Digulla's third option. It will give far better performance than anything else. Its called slicing. Read about it here http://docs.python.org/2/tutorial/introduction.html#strings
print string[::-1]
Sorry in advance if this is something really easy, I'm very new to Python. This seems like it should be something very simple, but I am having a frustratingly hard time finding an answer online.
I'm writing a Python script in a preliminary, pseudo sort of fashion at the moment, and don't have all variable defined yet. I want to be able to have comments in the middle of a line to symbolize where the variable will go, but without commenting out the entire rest of the line to the right.
To visualize what I mean, this is how what I want is done in C/C++:
int some_variable = /*some_variable_that_doesnt_exist_yet*/ + an_existing_variable;
Basically I need to be able to comment the middle of a line without commenting the left or right sides of said comment. Is there any way to do this?
I know there's a way to do it like this (or something similar to this):
some_variable = #some_variable_that_doesnt_exist_yet
\+ an_existing_variable
...but I'd rather not do it that way if possible, just for ease of reading.
Unfortunately no. But you can always break things into multiple lines and comment in between. Parentheses come in handy for that.
my_var = (#some_variable +
some_other_var)
As with any language switch you will need to learn new habits that fit the features of the language. Python does not have the feature you desire, you could use some horrendous hack to force something that looks a bit similar in but I rather suggest you don't.
Some options are: document the TODO on a neighbouring line, perhaps using docstrings; don't sweat it and figure you'll add it later when your tests start requiring it; or use the fact that variables are lightweight and just create them with dummy values that leave the final calculation unchanged.
Inline comments do not exist in python.
The closest that I know of is the use of strings:
int some_variable = "some_variable_that_doesnt_exist_yet +" and an_existing_variable;
But that is terrible, and you should never do that.
You can't: According to the documentation, comments in Python start with the hash character (#) and extend to the end of the physical line. See An Informal Introduction to Python.
Why not use something like:
name = "Use this for something later"
:
:
name = 27
Python does not have inline or block comments like this. You can add a string (or any other expression), as suggested by others, but you will have to make sure to (consistently) replace all of those placeholders, which is extremely error prone
If it's only the value of the variable that is missing or unclear, and not the variable itself, how about this:
variable_to_be_defined = None # TODO define me!
some_other_variable = variable_to_be_defined + an_existing_variable
If you are a bash/posix sh wizard you will know the $(command substition) feature in bash, which could even be inserted in a string. For example,
$ echo "I can count: $(seq 1 10 | tr -d '\n')"
I can count: 12345678910
You can imagine all wild things to do with this, especially to make a dynamically formed string. No need to do if..else block outside the string; just embed the code inside! I am s spoiled by this feature. So here's the question: in python, can we do something similar? Is there one person already devising a module to accomplish this task?
(Just a side comment: admittedly having this kind of feature is powerful but also opening yourself to a security risk. The program can be vulnerable to code injection. So think thoroughly before doing this especially with a foreign string coming from outside the code.)
You can use eval() and all of it's potential risks...
Some good links here and here
See the built-in eval() function.
Are you looking for an fstring:
Instead of starting the string with '
We start the string with f'
And whenever we want to embed any script we just put inside these: {}
I am a totally blind programmer who would like to learn Python. Unfortunately the fact that code blocks are represented with different levels of indentation is a major stumbling block. I was wondering if there were any tools available that would allow me to write code using braces or some other code block delimiter and then convert that format into a properly indented representation that the Python interpreter could use?
There's a solution to your problem that is distributed with python itself. pindent.py, it's located in the Tools\Scripts directory in a windows install (my path to it is C:\Python25\Tools\Scripts), it looks like you'd have to grab it from svn.python.org if you are running on Linux or OSX.
It adds comments when blocks are closed, or can properly indent code if comments are put in. Here's an example of the code outputted by pindent with the command:
pindent.py -c myfile.py
def foobar(a, b):
if a == b:
a = a+1
elif a < b:
b = b-1
if b > a: a = a-1
# end if
else:
print 'oops!'
# end if
# end def foobar
Where the original myfile.py was:
def foobar(a, b):
if a == b:
a = a+1
elif a < b:
b = b-1
if b > a: a = a-1
else:
print 'oops!'
You can also use pindent.py -r to insert the correct indentation based on comments (read the header of pindent.py for details), this should allow you to code in python without worrying about indentation.
For example, running pindent.py -r myfile.py will convert the following code in myfile.py into the same properly indented (and also commented) code as produced by the pindent.py -c example above:
def foobar(a, b):
if a == b:
a = a+1
elif a < b:
b = b-1
if b > a: a = a-1
# end if
else:
print 'oops!'
# end if
# end def foobar
I'd be interested to learn what solution you end up using, if you require any further assistance, please comment on this post and I'll try to help.
I personally doubt that there currently is at the moment, as a lot of the Python afficionados love the fact that Python is this way, whitespace delimited.
I've never actually thought about that as an accessibility issue however. Maybe it's something to put forward as a bug report to Python?
I'd assume that you use a screen reader here however for the output? So the tabs would seem "invisible" to you? With a Braille output, it might be easier to read, but I can understand exactly how confusing this could be.
In fact, this is very interesting to me. I wish that I knew enough to be able to write an app that will do this for you.
I think it's definately something that I'll put in a bug report for, unless you've already done so yourself, or want to.
Edit: Also, as noted by John Millikin There is also PyBraces Which might be a viable solution to you, and may be possible to be hacked together dependant on your coding skills to be exactly what you need (and I hope that if that's the case, you release it out for others like yourself to use)
Edit 2: I've just reported this to the python bug tracker
Although I am not blind, I have heard good things about Emacspeak. They've had a Python mode since their 8.0 release in 1998 (they seem to be up to release 28.0!). Definitely worth checking out.
You should be able to configure your editor to speak the tabs and spaces -- I know it's possible to display whitespace in most editors, so there must be an accessibility option somewhere to speak them.
Failing that, there is pybraces, which was written as a practical joke but might actually be useful to you with a bit of work.
If you're on Windows, I strongly recommend you take a look at EdSharp from:
http://empowermentzone.com/EdSharp.htm
It supports all of the leading Windows screenreaders, it can be configured to speak the indentation levels of code, or it has a built in utility called PyBrace that can convert to and from braces syntax if you want to do that instead, and it supports all kinds of other features programmers have come to expect in our text editors. I've been using it for years, for everything from PHP to JavaScript to HTML to Python, and I love it.
All of these "no you can't" types of answers are really annoying. Of course you can.
It's a hack, but you can do it.
http://timhatch.com/projects/pybraces/
uses a custom encoding to convert braces to indented blocks before handing it off to the interpreter.
As an aside, and as someone new to python - I don't accept the reasoning behind not even allowing braces/generic block delimiters ... apart from that being the preference of the python devs. Braces at least won't get eaten accidentally if you're doing some automatic processing of your code or working in an editor that doesn't understand that white space is important. If you're generating code automatically, it's handy to not have to keep track of indent levels. If you want to use python to do a perl-esque one-liner, you're automatically crippled. If nothing else, just as a safeguard. What if your 1000 line python program gets all of its tabs eaten? You're going to go line-by-line and figure out where the indenting should be?
Asking about it will invariably get a tongue-in-cheek response like "just do 'from __ future __ import braces'", "configure your IDE correctly", "it's better anyway so get used to it" ...
I see their point, but hey, if i wanted to, i could put a semicolon after every single line. So I don't understand why everyone is so adamant about the braces thing. If you need your language to force you to indent properly, you're not doing it right in the first place.
Just my 2c - I'm going to use braces anyway.
I appreciate your problem, but think you are specifying the implementation instead of the problem you need solved. Instead of converting to braces, how about working on a way for your screen reader to tell you the indentation level?
For example, some people have worked on vim syntax coloring to represent python indentation levels. Perhaps a modified syntax coloring could produce something your screen reader would read?
Searching an accessible Python IDE, found this and decided to answer.
Under Windows with JAWS:
Go to Settings Center by pressing JawsKey+6 (on the number row above the letters) in your favorite text editor. If JAWS prompts to create a new configuration file, agree.
In the search field, type "indent"
There will be only one result: "Say indent characters". Turn this on.
Enjoy!
The only thing that is frustrating for us is that we can't enjoy code examples on websites (since indent speaking in browsers is not too comfortable — it generates superfluous speech).
Happy coding from another Python beginner).
I use eclipse with the pydev extensions since it's an IDE I have a lot of experience with. I also appreciate the smart indentation it offers for coding if statements, loops, etc. I have configured the pindent.py script as an external tool that I can run on the currently focused python module which makes my life easier so I can see what is closed where with out having to constantly check indentation.
There are various answers explaining how to do this. But I would recommend not taking this route. While you could use a script to do the conversion, it would make it hard to work on a team project.
My recommendation would be to configure your screen reader to announce the tabs. This isn't as annoying as it sounds, since it would only say "indent 5" rather than "tab tab tab tab tab". Furthermore, the indentation would only be read whenever it changed, so you could go through an entire block of code without hearing the indentation level. In this way hearing the indentation is no more verbose than hearing the braces.
As I don't know which operating system or screen reader you use I unfortunately can't give the exact steps for achieving this.
Edsger Dijkstra used if ~ fi and do ~ od in his "Guarded Command Language", these appear to originate from the Algol68. There were also some example python guarded blocks used in RosettaCode.org.
fi = od = yrt = end = lambda object: None;
class MyClass(object):
def myfunction(self, arg1, arg2):
for i in range(arg1) :# do
if i > 5 :# then
print i
fi
od # or end(i) #
end(myfunction)
end(MyClass)
Whitespace mangled python code can be unambiguously unmangled and reindented if one uses
guarded blocks if/fi, do/od & try/yrt together with semicolons ";" to separate statements. Excellent for unambiguous magazine listings or cut/pasting from web pages.
It should be easy enough to write a short python program to insert/remove the guard blocks and semicolons.