473,406 Members | 2,377 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,406 software developers and data experts.

Evaluation of a comparison in combination with the in operator

bvdet
2,851 Expert Mod 2GB
I ran into something that seemed strange at first. I knew you could chain comparisons like x < y < z which evaluates to x < y and y < z. I did not realize this works in a similar manner:
Expand|Select|Wrap|Line Numbers
  1. >>> x = '21'
  2. >>> s = ['21', '22', '23']
  3. >>> y = '21'
  4. >>> y == '21' in s
  5. True
  6. # evaluates as y == '21' and '21' in s
  7. >>> y = "20"
  8. >>> y == "20" in s
  9. False
  10. # evaluates as y == '20' and '20' in s
It's not really a question, but tell me if I am understanding this incorrectly.

BV
Oct 29 '09 #1
1 1461
Glenton
391 Expert 256MB
that is interesting. not very intuitive
Nov 5 '09 #2

Sign in to post your reply or Sign up for a free account.

Similar topics

3
by: marco_segurini | last post by:
Hi, when the following code is executed bool Test1(); bool Test2(); .... if (Test1() || Test2()) { ... } ....
8
by: der | last post by:
Hello all, I've a question about order of evaluations in expressions that have && and || operators in them. The question is: will the evalution go left-to-right, no matter what -- even if the...
21
by: dragoncoder | last post by:
Consider the following code. #include <stdio.h> int main() { int i =1; printf("%d ,%d ,%d\n",i,++i,i++); return 0; }
77
by: berns | last post by:
Hi All, A coworker and I have been debating the 'correct' expectation of evaluation for the phrase a = b = c. Two different versions of GCC ended up compiling this as b = c; a = b and the other...
2
by: eastern_strider | last post by:
I'm running into problems about defining a comparison function for a map which has a user defined key. For example: class Key { public: string name; int number; Key (na, nu) : name (na),...
17
by: Dinsdale | last post by:
I would like to compare a string value to a pre-determined list of other strings. Is there a simple way to do this in one statements like this: if(strMystring.ToUpper() == ("STRING1"| "STRING2"|...
5
by: Jim Devenish | last post by:
I want to create a column alias to represent the comparison of two columns (ie a boolean result of True or False). A simple example is: Select VehicleFinanceID, SalePrice > PurchasePrice As...
9
by: sturlamolden | last post by:
Python allows the binding behaviour to be defined for descriptors, using the __set__ and __get__ methods. I think it would be a major advantage if this could be generalized to any object, by...
54
by: Rasjid | last post by:
Hello, I have just joined and this is my first post. I have never been able to resolve the issue of order of evaluation in C/C++ and the related issue of precedence of operators, use of...
39
by: Boltar | last post by:
Why does C do lazy evaluation for logical boolean operations but not bitwise ones? Ie: the following program prints "1 2" , not "1 1" under gcc main() { int a = 1; int b = 1; 0 && ++a;
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
0
BarryA
by: BarryA | last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers,...
0
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.