I face this issue and can't seem to find a fix except with Scipy or Numpy, both of which I don't wanna use in this case.
From a .csv file, I want to extract the values of the first column :
enter image description here
Which I manage to do with the following code :
mat_data = open('file.csv')
data_reader = csv.reader(mat_data)
list_data = list(data_reader)
value1=float(list_data[1][0])
value2=float(list_data[2][0])
value3=float(list_data[3][0])
I'd now like to create a loop that could be used and create value"i" no matter how many lines long my .csv is.
Any idea?
This did the trick for me !
mat_data = open('file.csv')
data_reader = csv.reader(mat_data)
list_data = list(data_reader)
i=0
value=dict()
for i in range(1,len(list_data)):
value[i]=list_data[i][0]
print value[i]
Related
I am trying to combine lists of information from different .txt files.
Example:
(text1.txt):
type1
type2
type3
(text2.txt):
variable1
variable2
variable3
I want the program to give me something like this:
(I can set the separator character but I will use ':' for the example)
type1:variable1
type1:variable2
type1:variable3
type2:variable1
type2:variable2
type2:variable3
type3:variable1
type3:variable2
type3:variable3
Does anyone know how I would even start to go about that in node.js
I know I can create an array from each file using this:
var txt1Array = fs.readFileSync('./text1.txt').toString().split("\n");
var txt2Array = fs.readFileSync('./text2.txt').toString().split("\n");
But after that, I don't know how to set up a for loop to add all of the text2 files after each text1 file data pieces.
EDIT: if anyone doesn't know, fs.readFileSync is how im getting the data from the different text files...
Something like that for example ?
const txt1Array = fs.readFileSync('./text1.txt').toString().split("\n");
const txt2Array = fs.readFileSync('./text2.txt').toString().split("\n");
const resultArray = [];
for (let str1 of txt1Array) {
for (let str2 of txt2Array) {
resultArray.push(`${str1}:${str2}`);
}
}
It seems too simple, maybe I didn't get right the question.
I'm really fresh to Python and need help reading information from txt file. I have a large C++ app need to duplicate it in Python. Sadly I have no idea where to start. I've been reading and watching some tutorials, but little help from them and I'm running out of time.
So my task is:
I have a shopping list with:
-Name of the item, price and age.
I also need to create two searches.
Search whether the item is in the shop (comparing strings).
if name of the item is == to the input name.
Search by age. Once the program finds the items, then it needs to print the list according to the price - from the lowest price to the highest.
For example you input age 15 - 30, the program prints out appropriate
items and sorts them by the price.
Any help would be nice. At least from where I could start.
Thank you.
EDITED
So far, I have this code:
class data:
price = 0
agefrom = 0
ageto = 0
name = ''
# File reading
def reading():
with open('toys.txt') as fd:
toyslist = []
lines = fd.readlines()
for line in lines:
information = line.split()
print(information)
"""information2 = {
'price': int(information[1])
'ageftom': int(information[2])
'ageto': int(information[3])
#'name': information[4]
}"""
information2 = data()
information2.price = int(information[0])
information2.agefrom = int(information[1])
information2.ageto = int(information[2])
information2.name = information[3]
toyslist.append(information2)
return toyslist
information = reading()
I HAVE A PROBLEM WITH THIS PART. I want to compare the user's input with the item information in the txt file.
n_search = raw_input(" Please enter the toy you're looking for: ")
def name_search(information):
for data in information:
if data.name == n_search:
print ("We have this toy.")
else:
print ("Sorry, but we don't have this toy.")
If you want to fins something in a list it's generally as straightforward as:
if "apple" in ["tuna", "pencil", "apple"]
However, in your case, the list to search is a list of lists so you need to "project" it somehow. List comprehension is often the easiest to reason about, a sort of for loop in a for loop.
if "apple" in [name for name,price,age in [["tuna",230.0,3],["apple",0.50,1],["pencil",1.50,2]]]
From here you want to start looking at filters whereby you provide a function that determines whether an entry is matched or not. you can roll your own in a for loop or use something more functional like 'itertools'.
Sorting on a list is also easy, just use 'sorted(my_list)' supplying a comparator function if you need it.
Examples as per your comment...
class ShoppingListItem:
def __init__(self,name,price,age):
self.name=name
self.price=price
self.age=age
or
from collections import namedtuple
sli = namedtuple("ShoppingListItem",['name','age','price'])
While trying to make a simple register/signup client only application for a personal project. I'm trying to load a list of users from a file, and compare them to a possible username. If the username already exists, the program will give them an error.
Here is a condensed clone of the code:
u1 = str(input("Input username: "))
t = open("userlistfile","r")
userlist = t.readline()
y = 0
for x in range(0, len(userlist)-1):
if userlist[y] == u1:
print("\n !Error: That username (",u1,") is already taken!")
y += 1
The user list is stored in a file so that it can opened, appended, and saved again, without being stored in the program. My current issue is that the userlist is saved as a string rather than an array. Is there a better way to do this? Thank you.
EDIT: Thanks to user lorenzo for a solution. My Friends are telling me to post a quick (really simple) copy of a for you guys who can't figure it out.
New code:
u1 = str(input("Input username: "))
t = open("userlistfile","r")
userlist = t.read() #Readline() changed to Read()
userlist = userlist.split('--') #This line is added
y = 0
for x in range(0, len(userlist)-1):
if userlist[y] == u1:
print("\n !Error: That username (",u1,") is already taken!")
y += 1
Example text file contents:
smith123--user1234--stacky
This line will seperate the string at the ('--') seperators and append each split part into an array:
userlist = userlist.split('--')
#Is used so that this (in the text file)
Smith123--user1234--stacky
#Becomes (in the program)
userlist = ['Smith123','user1234','stacky']
Sorry for the long post... Found it very interesting. Thanks again to Lorenzo :D.
userlist = t.readline()
reads one line from the file as a string. Iterating, then, gets characters in the string rather than words.
You should be able to get a list of strings (words) from a string with the split() method of strings or the more general re.split() function.
My code has 2 parts. First part is an automatic file opening programmed like this :
fichierref = 'H:\MATLAB\Archive_08112012';
files = dir(fullfile(fichierref, '*.txt'));
numberOfFiles = numel(files);
delimiterIn = ' ';
headerlinesIn = 11;
for d = 1:numberOfFiles
filenames(d) = cellstr(files(d).name);
end
for i=1:numberOfFiles
data = importdata(fullfile(fichierref,filenames{i}),delimiterIn,headerlinesIn);
end
Later on, I want the user to select his files for analysis. There's a problem with this though. I typed the lines as follow :
reference = warndlg('Choose the files from which you want to know the magnetic field');
uiwait(reference);
filenames = uigetfile('./*.txt','MultiSelect', 'on');
numberOfFiles = numel(filenames);
delimiterIn = ' ';
headerlinesIn = 11;
It's giving me the following error, after I press OK on the prompt:
Cell contents reference from a non-cell array object.
Error in FreqVSChampB_no_spec (line 149)
data=importdata(filenames{1},delimiterIn,headerlinesIn);
I didn't get the chance to select any text document. Anyone has an idea why it's doing that?
uigetfile is a bit of an annoying when used with `MultiSelect': when you select multiple files the output is returned as a cell array (of strings). However, when only one file is selected the output is of type string (not a cell array with a single cell, as one would have expected).
So, in order to fix this:
filenames = uigetfile('./*.txt','MultiSelect', 'on');
if ~iscell(filenames) && ischar( a )
filenames = {filenames}; % force it to be a cell array of strings
end
% continue your code here treating filenames as cell array of strings.
EDIT:
As pointed out by #Sam one MUST verify that the user did not press 'cancel' on the UI (by checking that filenames is a string).
I'm trying to find a way to count my columns coming from a Flat File. Actually, all my columns are concatened in a signe cell, sepatared with a '|' ,
after various attempts, it seems that only a script task can handle this.
Does anyone can help me upon that ? I've shamely no experience with script in C# ou VB.
Thanks a lot
Emmanuel
To better understand, below is the output of what I want to achieve to. e.g a single cell containing all headers coming from a FF. The thing is, to get to this result, I appended manually in the previous step ( derived column) all column names each others in order to concatenate them with a '|' separator.
Now , if my FF source layout changes, it won't work anymore, because of this manualy process. So I think I would have to use a script instead which basically returns my number of columns (header ) in a variable and will allow to remove the hard coded part in the derived column transfo for instance
This is an very old thread; however, I just stumbled on a similar problem. A flat file with a number of different record "formats" inside. Many different formats, not in any particular order, meaning you might have 57 fields in one line, then 59 in the next 1000, then 56 in the next 10000, back to 57... well, think you got the idea.
For lack of better ideas, I decided to break that file based on the number of commas in each line, and then import the different record types (now bunched together) using SSIS packages for each type.
So the answer for this question is there, with a bit more code to produce the files.
Hope this helps somebody with the same problem.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace OddFlatFile_Transformation
{
class RedistributeLines
{
/*
* This routine opens a text file and reads it line by line
* for each line the number of "," (commas) is counted
* and then the line is written into a another text file
* based on that number of commas found
* For example if there are 15 commas in a given line
* the line is written to the WhateverFileName_15.Ext
* WhaeverFileName and Ext are the same file name and
* extension from the original file that is being read
* The application tests WhateverFileName_NN.Ext for existance
* and creates the file in case it does not exist yet
* To Better control splited records a sequential identifier,
* based on the number of lines read, is added to the beginning
* of each line written independently of the file and record number
*/
static void Main(string[] args)
{
// get full qualified file name from console
String strFileToRead;
strFileToRead = Console.ReadLine();
// create reader & open file
StreamReader srTextFileReader = new StreamReader(strFileToRead);
string strLineRead = "";
string strFileToWrite = "";
string strLineIdentifier = "";
string strLineToWrite = "";
int intCountLines = 0;
int intCountCommas = 0;
int intDotPosition = 0;
const string strZeroPadding = "00000000";
// Processing begins
Console.WriteLine("Processing begins: " + DateTime.Now);
/* Main Loop */
while (strLineRead != null)
{
// read a line of text count commas and create Linde Identifier
strLineRead = srTextFileReader.ReadLine();
if (strLineRead != null)
{
intCountLines += 1;
strLineIdentifier = strZeroPadding.Substring(0, strZeroPadding.Length - intCountLines.ToString().Length) + intCountLines;
intCountCommas = 0;
foreach (char chrEachPosition in strLineRead)
{
if (chrEachPosition == ',') intCountCommas++;
}
// Based on the number of commas determined above
// the name of the file to be writen to is established
intDotPosition = strFileToRead.IndexOf(".");
strFileToWrite = strFileToRead.Substring (0,intDotPosition) + "_";
if ( intCountCommas < 10)
{
strFileToWrite += "0" + intCountCommas;
}
else
{
strFileToWrite += intCountCommas;
}
strFileToWrite += strFileToRead.Substring(intDotPosition, (strFileToRead.Length - intDotPosition));
// Using the file name established above the line captured
// during the text read phase is written to that file
StreamWriter swTextFileWriter = new StreamWriter(strFileToWrite, true);
strLineToWrite = "[" + strLineIdentifier + "] " + strLineRead;
swTextFileWriter.WriteLine (strLineToWrite);
swTextFileWriter.Close();
Console.WriteLine(strLineIdentifier);
}
}
// close the stream
srTextFileReader.Close();
Console.WriteLine(DateTime.Now);
Console.ReadLine();
}
}
}
Please refer my answers in the following Stack Overflow questions. Those answers might give you an idea of how to load a flat file that contains varying number of columns.
Example in the following question reads a file containing data separated by special character Ç (c-cedilla). In your case, the delimiter is Vertical Bar (|)
UTF-8 flat file import to SQL Server 2008 not recognizing {LF} row delimiter
Example in the following question reads an EDI file that contains different sections with varying number of columns. The package reads the file loads it accordingly with parent-child relationships into an SQL table.
how to load a flat file with header and detail parent child relationship into SQL server
Based on the logic used in those answers, you can also count the number of columns by splitting the rows in the file by the column delimiter (Vertical Bar |).
Hope that helps.