I have following list coming from file. what i want one of list of this file which containts many values duplicate one also
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['S', 'F', '3', '\n']
['7', '3', '4', '\n']
['7', '3', '4', '\n']
['7', '3', '4', '\n']
['7', '3', '4', '\n']
How to filter out only unique values.
import os
os.chdir('C:\\')
if os.path.exists('xxx.dat'):
airport = open('routes.dat')
for each_line in airport:
(Airlinecode,AirlineID,Source_airport_code,Source_airport_ID,Destination_airport,Destination_airport_ID,Codeshare,Stops,Equipment) = each_line.split("\t")
newlist =[]
newlist = Equipment
i = iter(newlist)
elements = []
for eachitem in range(len(newlist)):
elements.append(i.next())
print (elements)
airport.close()
else:
print('file does not exists')
For something like this where you are generating list of lists as output, you cannot simply put the items in a set (which does not allow duplicates) as lists are unhashable. What you could do is when generating the list, do something like:
seen = set()
key = "".join(newlist)
if key not in seen:
seen.add(key)
output.append(newlist)
If for some reason you cannot do this during the first iteration through the text file and only have access to the output array values, then you could loop through your output doing a similar technique and simply keep the unique values.
I have a XOR function:
string encryptDecrypt(string toEncrypt) {
char key[64] = { 'F', '2', 'D', 'C', '5', '4', '0', 'D', 'B', 'F', '3', 'E', '1', '2', '9', 'F', '4', 'E', 'A', 'A', 'F', '7', '6', '7', '5', '6', '9', 'E', '3', 'C', 'F', '9', '7', '5', '2', 'B', '4', 'B', '8', '2', '6', 'D', '9', '8', 'F', 'D', '8', '3', '8', '4', '6', '0', '8', '5', 'C', '0', '3', '7', 'D', '3', '5', 'F', '7', '5' };
string output = toEncrypt;
for (int i = 0; i < toEncrypt.size(); i++)
output[i] = toEncrypt[i] ^ key[i % (sizeof(key) / sizeof(char))];
return output;
}
I encrypted my .ini :
[test]
baubau = 1
haha = 2
sometext = blabla
How i tried to decrypt and use values:
std::string Filename = "abc.ini";
std::ifstream input(Filename, std::ios::binary | ios::in); // Open the file
std::string line; // Temp variable
std::vector<std::string> lines; // Vector for holding all lines in the file
while (std::getline(input, line)) // Read lines as long as the file is
{
lines.push_back(encryptDecrypt(line));
}
// Here i should call the ini reader? but how?
CIniReader iniReader("abc.ini");
string my = encryptDecrypt(iniReader.ReadString("test", "baubau", ""));
for (auto s : lines)
{
cout << my;
cout << endl;
}
Where is my mistake? Some help would be apreciated, Many Thanks!
What you can do is:
Read the file line by line, and break apart keys and values, i.e. where you see 'key=value' break it apart into key and value.
Encrypt the value.
Base64-encode the value, in case it is no longer valid text in the encoding of the file.
Replace the line with 'key=base64-encoded-value'.
Later, when you read the encoded value for the key, which is just a simple Base64-encoded string of bytes, Base64-decode the string, and the decrypt the value.
For example, this line:
baubau = 1
Take the value '1' as a string, and encrypt it with your function. The result in this case is a printable string 'w'. However, I would treat it as arbitrary bytes.
Base64-encode the "encrypted" value. For example, the Base64-encoding of 'w' in UTF-8 (or ASCII) is "dw==".
Replace the line with:
baubau = dw==
or, if you like:
baubau = "dw=="
Later, when you read the value for baubau, you simply Base64-decode 'dw==', obtaining 'w', and then decrypt 'w' to arrive at '1'.
I am a newbie at Python 2.7 and used the following code to create the list of observations pulled from a csv file.
import csv
data = []
with open(datafile,'rb') as f:
for row in f:
g=row
data.append(g)
It produces the following list (after reading the first row):
['01/01/2005,01:00,0,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,3,E,9,3,E,9,8.0,A,7,6.0,A,7,87,A,7,1013,A,7,150,A,7,2.1,A,7,16100,A,7,77777,A,7,1.1,E,8,0.099,F,8,0.160,F,8,0,1,A,7']
But when I use the following code to read the csv file and create the list:
data = []
with open(datafile,'rb') as f:
r = csv.reader(f)
for row in f
data = [row for row in r]
I get a list that looks as follows (after reading the first row):
['01/01/2005', '01:00', '0', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '3', 'E', '9', '3', 'E', '9', '8.0', 'A', '7', '6.0', 'A', '7', '87', 'A', '7', '1013', 'A', '7', '150', 'A', '7', '2.1', 'A', '7', '16100', 'A', '7', '77777', 'A', '7', '1.1', 'E', '8', '0.099', 'F', '8', '0.160', 'F', '8', '0', '1', 'A', '7']
This also appears to be a list (with the key difference being the apostrophes around each item in the list instead of just at the beginning and the end).
Since both appear to be lists, why does the code that uses data.append not deliver a similar list?
Your first list has just one single element -- a string holding the entire line, inclusing all the commas.
>>> l1 =['01/01/2005,01:00,0,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,0,2,0,3,E,9,3,E,9,8.0,A,7,6.0,A,7,87,A,7,1013,A,7,150,A,7,2.1,A,7,16100,A,7,77777,A,7,1.1,E,8,0.099,F,8,0.160,F,8,0,1,A,7']
>>> len(l1)
1
In your second example, csv.reader splits this line into several elements and puts those into the list.
>>> l2 = ['01/01/2005', '01:00', '0', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '0', '2', '0', '3', 'E', '9', '3', 'E', '9', '8.0', 'A', '7', '6.0', 'A', '7', '87', 'A', '7', '1013', 'A', '7', '150', 'A', '7', '2.1', 'A', '7', '16100', 'A', '7', '77777', 'A', '7', '1.1', 'E', '8', '0.099', 'F', '8', '0.160', 'F', '8', '0', '1', 'A', '7']
>>> len(l2)
68
Also note that the loop in your second example is somewhat odd. I assume that this is not your actual code, since there's a syntax error in it. It should probably rather be:
r = csv.reader(f)
for row in r: # row in r, not row in f
data.append(row) # append row to data -> 2d-array of items in rows
I have a 2D list:
[['Hard', '7', '27.00'], ['David', '4', '26.00'], ['Great', '2', '25.00']]
I want to print it out in alphabetical order based on the first index of each list. I have a variable called listName which stores the information as presented above. I have tried listName.sort() however, it does not sort in alphabetical order. Any suggestions?
You have to pass a key argument to sort(). This function will sort the elements (in your case, each element is a list) based on the first item (x[0]) of that element:
listName.sort(key = lambda x:x[0])
Note: This will sort the lists based on an ASCII comparison (please, correct me if I'm wrong), therefore, it will put uppercase before lowercase. For example:
listName = [['Hard', '7', '27.00'], ['David', '4', '26.00'], ['Great', '2', '25.00'], ['a', '3', '123']]
listName.sort(key = lambda x:x[0])
print(listName)
# [['David', '4', '26.00'], ['Great', '2', '25.00'], ['Hard', '7', '27.00'], ['a', '3', '123']]
Two more options:
# The data
listName = [['Hard', '7', '27.00'], ['David', '4', '26.00'], ['Great', '2', '25.00'], ['a', '3', '123']]
# Use first element for sorting using operator.itemgetter (like x[0])
from operator import itemgetter
sorted(listName, key=itemgetter(0))
# Use a function instead of a lambda (+ case insensitive sorting)
def get(x):
# return first element of sublist and convert to lowercase
return x[0].lower()
sorted(listName, key=get)
Lambdas and function are very similar:
lambda x: x[0]
def get(x): return x[0]
The difference is that functions have a name and lambdas are anonymous (unless stored in a variable). You must not use return in a lambda, its behavior is always like there is one.