python-2.x

问题 I'm trying to use tf.case (https://www.tensorflow.org/api_docs/python/tf/case) to conditionally update a Tensor. As shown, I'm trying to update learning_rate to 0.01 when global_step == 2 , and to 0.001 when global_step == 4 . However, when global_step == 2 , I already get learning_rate = 0.001 . Upon further inspection, it looks like tf.case is giving me the wrong result when global_step == 2 (I get 0.001 instead of 0.01 ). This is happening even though the predicate for 0.01 is evaluating

问题 I'm speaking about the general case. Here's an example: c = 1 def a(): def b(): print(c) b() c = 2 a() This code will return the following error: NameError: free variable 'c' referenced before assignment in enclosing scope . While the logical assumption is that the output should be 1 . What is the Pythonic solution to this issue? Use the global or nonlocal statements (which I don't like)? Maybe just avoid such situations, where multiple scopes share variables with identical names? 回答1:

问题 I want to remove doc strings from a Python program but leave asserts (and __debug__ sections) in. I have been using the -OO flag to generate .pyo files but according to the documentation that removes both asserts and doc strings. I'm using CPython 2.7. Clarification: I'm removing the docstrings as a cheap obfuscation method. Management made that decision and I think whether that is a useful thing to do is outside the scope of this question. 回答1: You can't have half of -O . It removes

问题 I am trying to make a basic card game using PyGame. I am currently just trying to draw a single card to the screen. The weird thing is, occasionally it will draw and occasionally it won't. Below is my code: import pygame from pygame.locals import * from socket import * import sys import os import math import getopt import random def load_png(name) : # Loads an image and returns the image object fullname = os.path.join('/home/edge/Downloads/Playing Cards/PNG-cards-1.3', name) image = pygame

问题 >>> class Yeah(object): ... def __eq__(self, other): ... return True ... >>> class Nah(object): ... def __eq__(self, other): ... return False ... >>> y = Yeah() >>> n = Nah() >>> y == n True >>> n == y False The left guy wins because when python2 sees x == y it tries x.__eq__(y) first. Is there any way to modify Nah so that he will win both times? My use-case is making something like this: class EqualsAnyDatetime(object): def __eq__(self, other): return isinstance(other, datetime) It just

问题 I am trying to install and use dolfin on Arch Linux, with Python 2.7.3. What is the best way to find out what is causing segmentation faults such as these? $ python2 -c "import dolfin; print dolfin.__version__" [3] 6491 segmentation fault (core dumped) python2 -c "import dolfin; print dolfin.__version__" I have tried inspecting the core file through gdb: $ sudo systemd-coredumpctl gdb 6491 but they are always truncated: Reading symbols from /usr/bin/python2.7...(no debugging symbols found)..

问题 On Python 2.7, for dir in os.listdir("E:/Library/Documents/Old - Archives/Case"): print dir prints out: Danny.xlsx Dannyh.xlsx ~$??? ?? ?????? ??? ???? ???????.docx while this: # using a unicode literal for dir in os.listdir(u"E:/Library/Documents/Old - Archives/Case"): print dir prints out: Dan.xlsx Dann.xlsx Traceback (most recent call last): File "E:\...\FirstModule.py", line 31, in <module> print dir File "C:\Python27\lib\encodings\cp1252.py", line 12, in encode return codecs.charmap

问题 This question already has answers here : Python dictionary: are keys() and values() always the same order? (8 answers) Closed 2 years ago . This question arises from this answer where one user uses d.keys() and d.values() separately to initialise a dataframe. It's common knowledge that dictionaries in python versions under 3.6 are not ordered. Consider a generic dictionary of the form: d = {k1 : v1, k2 : v2, k3 : v3} Where the keys k* are any hashable objects, and the values v* being any

问题 Code: import types class C(object): pass c = C() print(isinstance(c, types.InstanceType)) Output: False What correct way to check if object is instance of user-defined class for new-style classes? UPD: I want put additional emphasize on if checking if type of object is user-defined . According to docs: types.InstanceType The type of instances of user-defined classes. UPD2: Alright - not "correct" ways are OK too. UPD3: Also noticed that there is no type for set in module types 回答1: You can

问题 Code: import types class C(object): pass c = C() print(isinstance(c, types.InstanceType)) Output: False What correct way to check if object is instance of user-defined class for new-style classes? UPD: I want put additional emphasize on if checking if type of object is user-defined . According to docs: types.InstanceType The type of instances of user-defined classes. UPD2: Alright - not "correct" ways are OK too. UPD3: Also noticed that there is no type for set in module types 回答1: You can