I think a more reliable way of closing a connection is to tell the sever explicitly to close it in a way compliant with HTTP specification: HTTP/1.1 defines the “close” connection option for the sender to signal that the connection will be closed after completion of the response. For example, Connection: close in either the … Read more
Unlike in Python 2, the zip function in Python 3 returns an iterator. Iterators can only be exhausted (by something like making a list out of them) once. The purpose of this is to save memory by only generating the elements of the iterator as you need them, rather than putting it all into memory … Read more
from pprint import pprint pprint(the_list)
>>> dict([(‘A’, 1), (‘B’, 2), (‘C’, 3)]) {‘A’: 1, ‘C’: 3, ‘B’: 2}
You do it like this: First you disable your network card’s automatic checksumming: sudo ethtool -K eth1 tx off And then send your dodgy frame from python 2 (You’ll have to convert to Python 3 yourself): #!/usr/bin/env python from socket import socket, AF_PACKET, SOCK_RAW s = socket(AF_PACKET, SOCK_RAW) s.bind((“eth1”, 0)) # We’re putting together an … Read more
This can be done explicitly. class ref: def __init__(self, obj): self.obj = obj def get(self): return self.obj def set(self, obj): self.obj = obj a = ref([1, 2]) b = a print(a.get()) # => [1, 2] print(b.get()) # => [1, 2] b.set(2) print(a.get()) # => 2 print(b.get()) # => 2
Take a look at this PDF starting at page 38, ~slide I-77 and you’ll find all the info you need. Of course the rest of the slides are amazing, too, but those specifically deal with your issue: import time def follow(thefile): thefile.seek(0,2) # Go to the end of the file while True: line = thefile.readline() … Read more
The (previously) top-voted answer to this question is nicely formatted but absolutely wrong about performance. Let me demonstrate Performance Top Import import random def f(): L = [] for i in xrange(1000): L.append(random.random()) for i in xrange(1000): f() $ time python import.py real 0m0.721s user 0m0.412s sys 0m0.020s Import in Function Body def f(): import … Read more
There is now a section of the documentation describing how color mapping and normalization works The way that matplotlib does color mapping is in two steps, first a Normalize function (wrapped up by the sub-classes of matplotlib.colors.Normalize) which maps the data you hand in to [0, 1]. The second step maps values in [0,1] -> … Read more
edit: scipy 0.19 now has scipy.sparse.save_npz and scipy.sparse.load_npz. from scipy import sparse sparse.save_npz(“yourmatrix.npz”, your_matrix) your_matrix_back = sparse.load_npz(“yourmatrix.npz”) For both functions, the file argument may also be a file-like object (i.e. the result of open) instead of a filename. Got an answer from the Scipy user group: A csr_matrix has 3 data attributes that matter: .data, … Read more