I want to use printing command bellow in many places of my script. But I need to keep replacing "Survived" with some other string.
print(df.Survived.value_counts())
Can I automate the process by formating variable the same way as string? So if I want to replace "Survived" with "different" can I use something like:
var = 'different'
text = 'df.{}.value_counts()'.format(var)
print(text)
unfortunately this prints out "df.different.value_counts()" as as a string, while I need to print the value of df.different.value_counts()
I'm pretty sure alot of IDEs, have this option that is called refactoring, and it allows you to change a similar line of code/string on every line of code to what you need it to be.
I'm aware of VSCode's way of refactoring, is by selecting a part of the code and right click to select the option called change all occurances. This will replace the exact code on every line if it exists.
But if you want to do what you proposed, then eval('df.{}.value_counts()'.format(var)) is an option, but this is very unsecured and dangerous, so a more safer approach would be importing the ast module and using it's literal_eval function which is safer. ast.literal_eval('df.{}.value_counts()'.format(var)).
if ast.literal_eval() doesn't work then try this final solution that works.
def cat():
return 1
text = locals()['df.{}.value_counts'.format(var)]()
Found the way: print(df[var].value_counts())
I'm writing a script to scrape from another website with Python, and I am facing this question that I have yet to figure out a method to resolve it.
So say I have set to replace this particular string with something else.
word_replace_1 = 'dv'
namelist = soup.title.string.replace(word_replace_1,'11dv')
The script works fine, when the titles are dv234,dv123 etc.
The output will be 11dv234, 11dv123.
However if the titles are, dv234, mixed with dvab123, even though I did not set dvab to be replaced with anything, the script is going to replace it to 11dvab123. What should I do here?
Also, if the title is a combination of alphabits,numbers and Korean characters, say DAV123ㄱㄴㄷ,
how exactly should I make it to only spitting out DAV123, and adding - in between alphabits and numbers?
Python - making a function that would add "-" between letters
This gives me the idea to add - in between all characters, but is there a method to add - between character and number?
the only way atm I can think of is creating a table of replacing them, for example something like this
word_replace_3 = 'a1'
word_replace_4 = 'a2'
.......
and then print them out as
namelist3 = soup.title.string.replace(word_replace_3,'a-1').replace(word_replace_4,'a-2')
This is just slow and not efficient. What would be the best method to resolve this?
Thanks.
i´ve got small problem and before I spend even more time in trying to solve it i´d like to know if what I want to do is even possible ( and maybe input on how to do it^^).
My problem:
I want to take some text and then split it into different strings at every whitespace (for example "Hello my name is whatever" into "Hello" "my" "name" "is" "whatever").
Then I want to set every string with it´s own variable so that I get something alike to a= "Hello" b= "my" and so on. Then I want to compare the strings with other strings (the idea is to get addresses from applications without having to search through them so I thought I could copy a telephone book to define names and so on) and set matching input to variables like Firstname , LastName and street.
Then, and here comes the "I´d like to know if it´s possible" part I want it to put it into our database, this means I want it to copy the string into a text field and then to go to the next field via tab. I´ve done something like this before with AutoIT but i´ve got no idea how to tell AutoIT whats inside the strings so I guess it must be done through the programm itself.
I´ve got a little bit of experience with c++, python and BATCH files so it would be nice if anyone could tell me if this can even be done using those languages (and I fear C++ can do it and I´m just to stupid to do so).
Thanks in advance.
Splitting a string is very simple, there is usually a built in method called .split() which will help you, the method varies from language to language.
When you've done a split, it will be assigned to an array, you can then use an index to get the variables, for example you'd have:
var str = "Hello, my name is Bob";
var split = str.split(" ");
print split[0]; // is "Hello,"
print split[1]; // is "my" etc
You can also use JSON to return data so you could have an output like
print split["LastName"];
What you're asking for is defiantly possible.
Some links that could be useful:
Split a string in C++?
https://code.google.com/p/cpp-json/
this is my first time asking a question so let me know if I am doing something wrong (post wise)
I am trying to create a function that writes into a .txt but i seem to get two very different results between calling it from within a module, and writing the same loop in the shell directly. The code is as follows:
def function(para1, para2): #para1 is a string that i am searching for within para2. para2 is a list of strings
with open("str" + para1 +".txt", 'a'. encoding = 'utf-8') as file:
#opens a file with certain naming convention
n = 0
for word in para2:
if word == para1:
file.write(para2[n-1]+'\n')
print(para2[n-1]) #intentionally included as part of debugging
n+=1
function("targetstr". targettext)
#target str is the phrase I am looking for, targettext is the tokenized text I am
#looking through. this is in the form of a list of strings, that is the output of
#another function, and has already been 'declared' as a variable
when I define this function in the shell, I get the correct words appearing. However, when i call this same function through a module(in the shell), nothing appears in the shell, and the text file shows a bunch of numbers (eg: 's93161), and no new lines.
I have even gone to the extent of including a print statement right after declaration of the function in the module, and commented everything but the print statement, and yet nothing appears in the shell when I call it. However, the numbers still appear in the text file.
I am guessing that there is a problem with how I have defined the parameters or how i cam inputting the parameters when I call the function.
As a reference, here is the desired output:
‘She
Ashley
there
Kitty
Coates
‘Let
let
that
PS: Sorry if this is not very clear as I have very limited knowledge on speaking python
I have found the solution to issue. Turns out that I need to close the shell and restart everything before the compiler recognizes the changes made to the function in the module. Thanks to those who took a look at the issue, and those who tried to help.
I have seen a lot of C/C++ based solutions to this problem where we have to write a program that upon execution prints its own source.
some solutions --
http://www.cprogramming.com/challenges/solutions/self_print.html
Quine Page solution in many languages
There are many more solutions on the net, each different from the other. I wonder how do we approach to such a problem, what goes inside the mind of the one who solves it. Lend me some insights into this problem... While solutions in interpreted languages like perl, php, ruby, etc might be easy... i would like to know how does one go about designing it in compiled languages...
Aside from cheating¹ there is no difference between compiled and interpreted languages.
The generic approach to quines is quite easy. First, whatever the program looks like, at some point it has to print something:
print ...
However, what should it print? Itself. So it needs to print the "print" command:
print "print ..."
What should it print next? Well, in the mean time the program grew, so it needs to print the string starting with "print", too:
print "print \"print ...\""
Now the program grew again, so there's again more to print:
print "print \"print \\\"...\\\"\""
And so on.
With every added code there's more code to print.
This approach is getting nowhere,
but it reveals an interesting pattern:
The string "print \"" is repeated over and over again.
It would be nice to put the repeating part
into a variable:
a = "print \""
print a
However, the program just changed,
so we need to adjust a:
a = "a = ...\nprint a"
print a
When we now try to fill in the "...",
we run into the same problems as before.
Ultimately, we want to write something like this:
a = "a = " + (quoted contents of a) + "\nprint a"
print a
But that is not possible,
because even if we had such a function quoted() for quoting,
there's still the problem that we define a in terms of itself:
a = "a = " + quoted(a) + "\nprint a"
print a
So the only thing we can do is putting a place holder into a:
a = "a = #\nprint a"
print a
And that's the whole trick!
Anything else is now clear.
Simply replace the place holder
with the quoted contents of a:
a = "a = #\nprint a"
print a.replace("#", quoted(a))
Since we have changed the code,
we need to adjust the string:
a = "a = #\nprint a.replace(\"#\", quoted(a))"
print a.replace("#", quoted(a))
And that's it!
All quines in all languages work that way
(except the cheating ones).
Well, you should ensure that you replace only
the first occurence of the place holder.
And if you use a second place holder,
you can avoid needing to quote the string.
But those are minor issues
and easy to solve.
If fact, the realization of quoted() and replace()
are the only details in which the various quines really differ.
¹ by making the program read its source file
There are a couple of different strategies to writing quines. The obvious one is to just write code that opens the code and prints it out. But the more interesting ones involve language features that allow for self-embedding, like the %s-style printf feature in many languages. You have to figure out how to embed something so that it ends up resolving to the request to be embedded. I suspect, like palindromes, a lot of trial and error is involved.
The usual approach (when you can't cheat*) is to write something that encodes its source in a string constant, then prints out that constant twice: Once as a string literal, and once as code. That gets around the "every time I write a line of code, I have to write another to print it out!" problem.
'Cheating' includes:
- Using an interpreted language and simply loading the source and printing it
- 0-byte long files, which are valid in some languages, such as C.
For fun, I came up with one in Scheme, which I was pretty proud of for about 5 minutes until I discovered has been discovered before. Anyways, there's a slight modification to the "rules" of the game to better count for the duality of data and code in Lisp: instead of printing out the source of the program, it's an S-expression that returns itself:
((lambda (x) (list x `',x)) '(lambda (x) (list x `',x)))
The one on Wikipedia has the same concept, but with a slightly different (more verbose) mechanism for quoting. I like mine better though.
One idea to think about encoding and how to give something a double meaning so that it can be used to output something in a couple of forms. There is also the cavaet that this type of problem comes with restrictions to make it harder as without any rules other than the program output itself, the empty program is a solution.
How about actually reading and printing your source code? Its not difficult at all!! Heres one in php:
<?php
{
header("Content-Type: text/plain");
$f=fopen("5.php","r");
while(!feof($f))
{
echo fgetc($f);
}
fclose($f);
}
?>
In python, you can write:
s='c=chr(39);print"s="+c+s+c+";"+s';c=chr(39);print"s="+c+s+c+";"+s
inspired from this self printing pseudo-code:
Print the following line twice, the second time with quotes.
"Print the following line twice, the second time with quotes."
I've done a AS3 example for those interested in this
var program = "var program = #; function main(){trace(program.replace('#',
String.fromCharCode(34) + program + String.fromCharCode(34)))} main()";
function main(){
trace(program.replace('#', String.fromCharCode(34) + program + String.fromCharCode(34)))
}
main()
In bash it is really easy
touch test; chmod oug+x test; ./test
Empty file, Empty output
In ruby:
puts File.read(_ _ FILE _ _)