At the moment I am saving a set of variables to a text file. I am doing following to check if my code works, but whenever I use a two-digit numbers such as 10 it would not print this number as the max number.
If my text file looked like this.
tom:5
tom:10
tom:1
It would output 5 as the max number.
name = input('name')
score = 4
if name == 'tom':
fo= open('tom.txt','a')
fo.write('Tom: ')
fo.write(str(score ))
fo.write("\n")
fo.close()
if name == 'wood':
fo= open('wood.txt','a')
fo.write('Wood: ')
fo.write(str(score ))
fo.write("\n")
fo.close()
tomL2 = []
woodL2 = []
fo = open('tom.txt','r')
tomL = fo.readlines()
tomLi = tomL2 + tomL
fo.close
tomLL=max(tomLi)
print(tomLL)
fo = open('wood.txt','r')
woodL = fo.readlines()
woodLi = woodL2 + woodL
fo.close
woodLL=max(woodLi)
print(woodLL)
You are comparing strings, not numbers. You need to convert them into numbers before using max. For example, you have:
tomL = fo.readlines()
This contains a list of strings:
['tom:5\n', 'tom:10\n', 'tom:1\n']
Strings are ordered lexicographically (much like how words would be ordered in an English dictionary). If you want to compare numbers, you need to turn them into numbers first:
tomL_scores = [int(s.split(':')[1]) for s in tomL]
The parsing is done in the following way:
….split(':') separates the string into parts using a colon as the delimiter:
'tom:5\n' becomes ['tom', '5\n']
…[1] chooses the second element from the list:
['tom', '5\n'] becomes '5\n'
int(…) converts a string into an integer:
'5\n' becomes 5
The list comprehension [… for s in tomL] applies this sequence of operations to every element of the list.
Note that int (or similarly float) are rather picky about what it accepts: it must be in the form of a valid numeric literal or it will be rejected with an error (although preceding and trailing whitespace is allowed). This is why you need ….split(':')[1] to massage the string into a form that it's willing to accept.
This will yield:
[5, 10, 1]
Now, you can apply max to obtain the largest score.
As a side-note, the statement
fo.close
will not close a file, since it doesn't actually call the function. To call the function you must enclose the arguments in parentheses, even if there are none:
fo.close()
Related
For two given strings, is there a pythonic way to count how many consecutive characters of both strings (starting at postion 0 of the strings) are identical?
For example in aaa_Hello and aa_World the "leading matching characters" are aa, having a length of 2. In another and example there are no leading matching characters, which would give a length of 0.
I have written a function to achive this, which uses a for loop and thus seems very unpythonic to me:
def matchlen(string0, string1): # Note: does not work if a string is ''
for counter in range(min(len(string0), len(string1))):
# run until there is a mismatch between the characters in the strings
if string0[counter] != string1[counter]:
# in this case the function terminates
return(counter)
return(counter+1)
matchlen(string0='aaa_Hello', string1='aa_World') # returns 2
matchlen(string0='another', string1='example') # returns 0
You could use zip and enumerate:
def matchlen(str1, str2):
i = -1 # needed if you don't enter the loop (an empty string)
for i, (char1, char2) in enumerate(zip(str1, str2)):
if char1 != char2:
return i
return i+1
An unexpected function in os.path, commonprefix, can help (because it is not limited to file paths, any strings work). It can also take in more than 2 input strings.
Return the longest path prefix (taken character-by-character) that is a prefix of all paths in list. If list is empty, return the empty string ('').
from os.path import commonprefix
print(len(commonprefix(["aaa_Hello","aa_World"])))
output:
2
from itertools import takewhile
common_prefix_length = sum(
1 for _ in takewhile(lambda x: x[0]==x[1], zip(string0, string1)))
zip will pair up letters from the two strings; takewhile will yield them as long as they're equal; and sum will see how many there are.
As bobble bubble says, this indeed does exactly the same thing as your loopy thing. Its sole pro (and also its sole con) is that it is a one-liner. Take it as you will.
I want to input two comma separated strings: the first a set of strings, the second a set of ranges and return substrings based on ranges, for example:
x=input("Input string to search: ")
search=x.split(',')
y=input("Input numbers to locate: ")
numbers=y.split(',')
I would then like to use the second list of ranges to print out specified characters from the first list.
An example:
Input string to search: abcdefffg,aabcdefghi,bbcccdefghi
Input numbers to locate: 1:2,2:3,5:9
I would like the output to look like this:
bc
bcd
defghi
Any suggestions? Thanks in advance!
split(':') splits a "range" into its two components. map(int, ...) converts them to integers. string[a:b] takes characters at indices a through b.
zip is an easy way to read from two different lists combined.
Let me know if you have any other questions:
x = "abcdefffg,aabcdefghi,bbcccdefghi"
search = x.split(',')
y = "1:2,2:3,5:9"
numbers = y.split(',')
results = []
for string, rng in zip(search, numbers):
start, how_many = map(int, rng.split(':'))
results.append(string[start:start+how_many])
print(" ".join(results))
# Output:
# bc bcd defghi
I have a list of filenames in a struct array, example:
4x1 struct array with fields:
name
date
bytes
isdir
datenum
where files.name
ans =
ts.01094000.crest.csv
ans =
ts.01100600.crest.csv
etc.
I have another list of numbers (say, 1094000). And I want to find the corresponding file name from the struct.
Please note, that 1094000 doesn't have preceding 0. Often there might be other numbers. So I want to search for '1094000' and find that name.
I know I can do it using Regex. But I have never used that before. And finding it difficult to write for numbers instead of text using strfind. Any suggestion or another method is welcome.
What I have tried:
regexp(files.name,'ts.(\d*)1094000.crest.csv','match');
I think the regular expression you'd want is more like
filenames = {'ts.01100600.crest.csv','ts.01094000.crest.csv'};
matches = regexp(filenames, ['ts\.0*' num2str(1094000) '\.crest\.csv']);
matches = ~cellfun('isempty', matches);
filenames(matches)
For a solution with strfind...
Pre-16b:
match = ~cellfun('isempty', strfind({files.name}, num2str(1094000)),'UniformOutput',true)
files(match)
16b+:
match = contains({files.name}, string(1094000))
files(match)
However, the strfind way might have issues if the number you are looking for exists in unexpected places such as looking for 10 in ["01000" "00101"].
If your filenames match the pattern ts.NUMBER.crest.csv, then in 16b+ you could do:
str = {files.name};
str = extractBetween(str,4,'.');
str = strip(str,'left','0');
matches = str == string(1094000);
files(matches)
Given an input string map three types of possible sequences of numbers contained in the string to a single number and leave the other elements of the string unchanged:
Single number should be mapped to the char 1: "help3me" -> "help1me"
Two numbers in a row should be mapped to the char 2: "help18me" -> "help2me"
Three or more numbers in a row should be mapped to 3: "test3432help234312me" -> "test3help3me"
Our input strings can contain any number of 1,2,3+ length sequences of digits so that a valid input example is "help3490897test73me23435please5"
What is an effective solution for the above problem in Scala does it just involve enumerating through the three possible cases as a regex ?
Use regular expression and method replaceAllIn. The second argument is the function that takes Match object and transforms it to its length.
val str = "help3me34"
val expr = "(\\d+)".r
expr.replaceAllIn(str, x => (x.group(0).length min 3).toString)
res2: String = help1me2
I have a file that contains rows and columns of information like:
104857 Big Screen TV 567.95
573823 Blender 45.25
I need to parse this information into three separate items, a string containing the identification number on the left, a string containing the item name, and a double variable containing the price. The information is always found in the same columns, i.e. in the same order.
I am having trouble accomplishing this. Even when not reading from the file and just using a sample string, my attempt just outputs a jumbled mess:
string input = "104857 Big Screen TV 567.95";
string tempone = "";
string temptwo = input.substr(0,1);
tempone += temptwo;
for(int i=1 ; temptwo != " " && i < input.length() ; i++)
{
temptwo = input.substr(j,j);
tempone += temp2;
}
cout << tempone;
I've tried tweaking the above code for quite some time, but no luck, and I can't think of any other way to do it at the moment.
You can find the first space and the last space using std::find_first_of and std::find_last_of . You can use this to better split the string into 3 - first space comes after the first variable and the last space comes before the third variable, everything in between is the second variable.
How about following pseudocode:
string input = "104857 Big Screen TV 567.95";
string[] parsed_output = input.split(" "); // split input string with 'space' as delimiter
// parsed_output[0] = 104857
// parsed_output[1] = Big
// parsed_output[2] = Screen
// parsed_output[3] = TV
// parsed_output[4] = 567.95
int id = stringToInt(parsed_output[0]);
string product = concat(parsed_output[1], parsed_output[2], ... ,parsed_output[length-2]);
double price = stringToDouble(parsed_output[length-1]);
I hope, that's clear.
Well try breaking down the files components:
you know a number always comes first, and we also know a number has no white spaces.
The string following the number CAN have whitespaces, but won't contain any numbers(i would assume)
After this title, you're going to have more numbers(with no whitespaces)
from these components, you can deduce:
grabbing the first number is as simple as reading in using the filestream <<.
getting the string requires you to check until you reach a number, grabbing one character at a time and inserting that into a string. the last number is just like the first, using the filestream <<
This seems like homework so i'll let you put the rest together.
I would try a regular expression, something along these lines:
^([0-9]+)\s+(.+)\s+([0-9]+\.[0-9]+)$
I am not very good at regex syntax, but ([0-9]+) corresponds to a sequence of digits (this is the id), ([0-9]+\.[0-9]+) is the floating point number (price) and (.+) is the string that is separated from the two number by sequences of "space" characters: \s+.
The next step would be to check if you need this to work with prices like ".50" or "10".