Python 3超新手常犯的錯誤

##注意parameter的值是variable時，不會跟著variable的值來改變

t = 0

def p(a=t):
    print("a=%d"%a)

def main():
    global t
    t = 100
    p()
    print("t=%d"%t)

if __name__ == "__main__":
    main()

##############Output#############
a=0
t=100

Python3 "from m import *" 超新手常犯的錯誤

#在python 3, 請注意s的值並不會共用
# a.py
from b import *

def main():
    global s
    print(s)
    add()
    print(s)
    s += 6
    print(s)
    add()
    print(s)

if __name__ == "__main__":
    main()

# b.py
s =10

def add():
    global s
    s += 1
    print("s=%d"%s)

###
# Execute a.py
###
10
s=11
10
16
s=12
16

#如果要s的值共用，可以如下修改：
# a.py
import b

def main():
    print(b.s)
    b.add()
    print(b.s)
    b.s += 6
    print(b.s)
    b.add()
    print(b.s)

if __name__ == "__main__":
    main()

# b.py (不變)
s =10

def add():
    global s
    s += 1
    print("s=%d"%s)

###
# Execute a.py
###
10
s=11
11
17
s=18
18

Can't log in to ubuntu 12.04 (轉貼)

Can't log in to ubuntu 12.04

up vote2down votefavorite 1

I can't log in to my ubuntu 12.04. Once I login I got returned back to the original screen after a trial to enable X11 Forwarding. Can you help me with this. login shareimprove this question edited Jun 26 '12 at 19:44 Thomas W. 18.3k1357101 asked May 19 '12 at 20:40 Ahmed 16112

Are you trying to login remotely? What did you do to try to enable X11 forwarding? –  izx May 19 '12 at 21:40 Does this only happen when trying to log in remotely? Or are you having this problem logging in locally as well? –  Eliah Kagan Mar 27 '13 at 1:07 Check your .xsession-errors in your home directory, I found an error over there, fixed it, then I can login from desktop. I did try to change the permission and ownership of .Xauthority but it doesn't help in my case. – user288195 Jun 3 '14 at 23:25 add a comment

9 Answers

activeoldestvotes

up vote7down vote

I haven't tried to enable X11Forwarding, but I used to have the same problem. You can fix this in a few steps: When you get to the graphical login screen, hit Ctrl+Alt+F2, thus you get to a textual login. Put in your name and password (password is not displayed when you type, neither as stars or bullets). Type sudo apt-get install gdm and hit enter, give your password and wait to get a line ending with a dollar sign again. Type sudo dpkg-reconfigure gdm. Hit Enter at the first screen. Select gdm in the list you get in the second screen with the arrow keys. Hit the Tab button (above the caps lock one). Now you see the word Ok highlighted. Hit Enter. Type sudo reboot and hit enter. You'll get another graphical login screen, but you'll be able to log in! P.S.: If you are used to running some programs like ifconfig or others which are administrative ones from a terminal emulator (e.g. gnome-terminal) you'd better add a line like PATH="$PATH:/sbin:/usr/sbin" at the end of the .bashrc file in your home directory. You can do it with echo 'PATH="$PATH:/sbin:/usr/sbin"' >> ~/.bashrc. If you want to change back to the other graphical login screen from time to time and see if it was bug-fixed and it works again you can run sudo dpkg-reconfigure gdm and select lightdm and reboot (doesn't look like it works if you just run sudo pkill X). shareimprove this answer edited Sep 11 '13 at 14:42 jokerdino♦ 23.3k1888166 answered May 23 '12 at 10:53 Lorra 1841

Excel 2010中某些行隱藏的解法

常用->儲存格->格式->隱藏及取消隱藏->取消隱藏欄

Random Big Rich Man

Formosa (轉貼)

PTT標題前符號的意思 (轉貼)

【+】 還沒看過的文章，如果已看過 + 就會消失

【~】 就是這篇文章你已經看過，但只要是有新推文，或是原ＰＯ修了文，就會以此標記來提醒讀者說「此文章有新推文囉！」或是「此文章已被原ＰＯ修過囉！」

【M m】 這是被板主ｍ起來的文章，也就是認為重要，不該系統清除，或者是不讓原ＰＯ刪除的標記此標記，差別只在於，大Ｍ是未讀，小ｍ是已讀

【=】 就是m文內容有新變更，例如作者修改文章或是有人推文，看完就會變m

【!】 被版主標記起來，而此標記，為「鎖文」，通常是文章具爭議性，鎖起來，防止再戰下去也就是說，表示該篇文章不能推文、競標、回應

【S s】 被版主標記用，這標記通常是待處理、或已處理的文章，要看各板板主怎麼去使用也就是各板用途定義不同，大S是已讀，小s是未讀

 在我的最愛裡文章前的紅勾勾v是指你還沒有看過這個版上的最後一篇文章，如果看完就會消失，但有新文章就會出現

Ref:http://flowerhua888.pixnet.net/blog/post/82412341-ptt%E6%A8%99%E9%A1%8C%E5%89%8D%E7%AC%A6%E8%99%9F%E7%9A%84%E6%84%8F%E6%80%9D~