python-2.7

问题 Why is my algorithm for finding the sum of all prime numbers below 2 million so slow? I'm a fairly beginner programmer and this is what I came up with for finding the solution: import time sum = 2 start = time.time() for number in range(3, 2000000): prime = True for x in range(2, number): if number % x == 0: prime = False if prime: sum += number print "Sum =", sum end = time.time() - start print "Runtime =", end Can someone please help me out? Thanks! 回答1: Your algorithm uses trial division,

问题 I am new to Django. I got a Django rest project. When i run it, an error shows as from django.utils.importlib import import_module ImportError: No module named importlib I tried installing importlib with the command pip install importlib Then it shows Requirement already satisfied: importlib in ./lib/python2.7/site-packages/gcm/utils.py" So how coild i install importlib package? 回答1: You don't. importlib is part of python since v2.7. The project you want to run seems to be an old project that

问题 I am new to Django. I got a Django rest project. When i run it, an error shows as from django.utils.importlib import import_module ImportError: No module named importlib I tried installing importlib with the command pip install importlib Then it shows Requirement already satisfied: importlib in ./lib/python2.7/site-packages/gcm/utils.py" So how coild i install importlib package? 回答1: You don't. importlib is part of python since v2.7. The project you want to run seems to be an old project that

问题 I am attempting to pip install termios module and it gives me the following error Could not find a version that satisfies the requirement termios (from versions: ) No matching distribution found for termios I have attempted this on Python 2.7 and 3.5. On linux. 回答1: termios is part of the Python Standard Library, which means it comes with Python. It provides an interface to the POSIX terminal calls of the underlying OS, which means it only applies on POSIX platforms. So... If you're trying to

问题 I am attempting to pip install termios module and it gives me the following error Could not find a version that satisfies the requirement termios (from versions: ) No matching distribution found for termios I have attempted this on Python 2.7 and 3.5. On linux. 回答1: termios is part of the Python Standard Library, which means it comes with Python. It provides an interface to the POSIX terminal calls of the underlying OS, which means it only applies on POSIX platforms. So... If you're trying to

问题 I am using Python2.7, and I can't update it, and I have this line of code, which raise an error at the asterisk, and I don't know why? And how to fix! inp = tf.random.uniform(shape=[4, 6, 2], maxval=20, dtype=tf.int32) out = tf.math.reduce_max(inp, axis=2) am = tf.math.argmax(out, axis=1) o = tf.gather_nd(inp, [*enumerate(am)]) This code is about getting a 2D max Tensor from a 3D Tensor based on the maximum one value using TensorFlow 1.14. Like the image below illustrate: 回答1: The syntax

问题 I am using Python2.7, and I can't update it, and I have this line of code, which raise an error at the asterisk, and I don't know why? And how to fix! inp = tf.random.uniform(shape=[4, 6, 2], maxval=20, dtype=tf.int32) out = tf.math.reduce_max(inp, axis=2) am = tf.math.argmax(out, axis=1) o = tf.gather_nd(inp, [*enumerate(am)]) This code is about getting a 2D max Tensor from a 3D Tensor based on the maximum one value using TensorFlow 1.14. Like the image below illustrate: 回答1: The syntax

问题 I have a list of colors: initialColors = [u'black' u'black' u'black' u'white' u'white' u'white' u'powderblue' u'whitesmoke' u'black' u'cornflowerblue' u'powderblue' u'powderblue' u'goldenrod' u'white' u'lavender' u'white' u'powderblue' u'powderblue' u'powderblue' u'powderblue' u'powderblue' u'powderblue' u'powderblue' u'powderblue' u'white' u'white' u'powderblue' u'white' u'white'] And I have a labels for these colors like this: labels_train = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1

问题 This question already has answers here : What is the difference between list and list[:] in python? (7 answers) Closed 6 years ago . I am trying to learn Python. Can someone please help me understand the difference between following two: a = x vs a=x[:] 回答1: a = x creates a reference: a = [2] x = a print id(a) print id(x) Produces: 39727240 39727240 So if you alter a then x would change too because they are the same objects Whereas a = x[:] creates a new object a = [2] x = a[:] print id(a)

问题 This question already has answers here : What is the difference between list and list[:] in python? (7 answers) Closed 6 years ago . I am trying to learn Python. Can someone please help me understand the difference between following two: a = x vs a=x[:] 回答1: a = x creates a reference: a = [2] x = a print id(a) print id(x) Produces: 39727240 39727240 So if you alter a then x would change too because they are the same objects Whereas a = x[:] creates a new object a = [2] x = a[:] print id(a)