Suppose I have two differently-sized lists a = [1, 2, 3] b = ['a', 'b'] What is a Pythonic way to get a list of tuples c of all the possible combinations of one element from a and one element from b? >>> print c [(1, 'a'), (1, 'b'), (2, 'a'), (2, 'b'), (3, 'a'), (3, 'b')] The order of elements in c does not matter. The solution wi...
I need to open multiple files (2 input and 2 output files), do complex manipulations on the lines from input files and then append results at the end of 2 output files. I am currently using the following approach: in_1 = open(input_1) in_2 = open(input_2) out_1 = open(output_1, "w") out_2 = open(output_2, "w") # Read one line from each...
Problem Hey folks. I'm looking for some advice on python performance. Some background on my problem: Given: A (x,y) mesh of nodes each with a value (0...255) starting at 0 A list of N input coordinates each at a specified location within the range (0...x, 0...y) A value Z that defines the "neighborhood" in count of nodes Increm...
I very new to Python, and fairly new to regex. (I have no Perl experience.) I am able to use regular expressions in a way that works, but I'm not sure that my code is particularly Pythonic or consise. For example, If I wanted to read in a text file and print out text that appears directly between the words 'foo' and 'bar' in each line...
I create the following class: class Image(object): def __init__(self, extension, data, urls=None, user_data=None): self._extension = extension self._data = data self._urls = urls self._user_data = user_data self._hex_digest = hashlib.sha1(self._data).hexDigest() Images should be equal when a...
What is the usual/clearest way to write this in Python? value, _ = func_returning_a_tuple() or: value = func_returning_a_tuple()[0] ...
I'm doing it like: def set_property(property,value): def get_property(property): or object.property = value value = object.property I'm new to Python, so i'm still exploring the syntax, and i'd like some advice on doing this. ...
Using Python I need to insert a newline character into a string every 64 characters. In Perl it's easy: s/(.{64})/$1\n/ How could this be done using regular expressions in Python? Is there a more pythonic way to do it? ...
hello. What is the pythonic way to test if there is a tuple starting with another tuple in collection? actually, I am really after the index of match, but I can probably figure out from test example for example: c = ((0,1),(2,3)) # (0,) should match first element, (3,)should match no element I should add my python is 2.4 and/or 2.5...
Hello! I'm looking for a pythonic way of iterating over first n items of an iterable (upd: not a list in a common case, as for lists things are trivial), and it's quite important to do this as fast as possible. This is how I do it now: count = 0 for item in iterable: do_something(item) count += 1 if count >= n: break Doesn't seem ...
I've got a loop that wants to execute to exhaustion or until some user specified limit is reached. I've got a construct that looks bad yet I can't seem to find a more elegant way to express it; is there one? def ello_bruce(limit=None): for i in xrange(10**5): if predicate(i): if not limit is None: ...
I'm still learning python. I just wrote this method to determine if a player has won a game of tic-tac-toe yet, given a board state like: '[['o','x','x'],['x','o','-'],['x','o','o']]' def hasWon(board): players = ['x', 'o'] for player in players: for row in board: if row.count(player) == 3: return player top, m...
I have a Linux box and I want to be able to telnet into it (port 77557) and run few required commands without having to access to the whole Linux box. So, I have a server listening on that port, and echos the entered command on the screen. (for now) Telnet 192.168.1.100 77557 Trying 192.168.1.100... Connected to 192.168.1....
Hi, I have an uniform list of objects in python: class myClass(object): def __init__(self, attr): self.attr = attr self.other = None objs = [myClass (i) for i in range(10)] Now I want to extract a list with some attribute of that class (let's say attr), in order to pass it so some function (for plotting that data ...
Hello Everybody, I want to get the index of the min value of a numpy array that contains NaNs and I want them ignored >>> a = array([ nan, 2.5, 3., nan, 4., 5.]) >>> a array([ NaN, 2.5, 3. , NaN, 4. , 5. ]) if I run argmin, it returns the index of the first NaN >>> a.argmin() 0 I substitute NaNs with Infs a...
Hello Everybody, I need a function that returns non-NaN values from an array. Currently I am doing it this way: >>> a = np.array([np.nan, 1, 2]) >>> a array([ NaN, 1., 2.]) >>> np.invert(np.isnan(a)) array([False, True, True], dtype=bool) >>> a[np.invert(np.isnan(a))] array([ 1., 2.]) Python: 2.6.4 numpy: 1.3.0 Please share...
Hello Everybody, I have a list of values and I want to put them in a dictionary that would map each value to it's index. I can do it this way: >>> t = (5,6,7) >>> d = dict(zip(t, range(len(t)))) >>> d {5: 0, 6: 1, 7: 2} this is not bad, but I'm looking for something more elegant. I've come across the following, but it does the opp...
Suppose I have a list of elements and I want to randomly select an element from the list that satisfies a predicate. What is the pythonic way of doing this? I currently do a comprehension followed by a random.choice() but that is unnecessarily inefficient : intlist = [1,2,3,4,5,6,7,8,9] evenlist = [ i for i in intlist if i % 2 == 0 ]...
Is there a more pythonic way of doing this? I am trying to find the eight neighbours of an integer coordinate lying within an extent. I am interested in reducing its verbosity without sacrificing execution speed. def fringe8((px, py), (x1, y1, x2, y2)): f = [(px - 1, py - 1), (px - 1, py), (px - 1, py + 1), ...
I have a particular case where using compound dictionary keys would make a task easier. I have a working solution, but feel it is inelegant. How would you do it? context = { 'database': { 'port': 9990, 'users': ['number2', 'dr_evil'] }, 'admins': ['[email protected]', '[email protected]'], 'domain....