Just some Boolean values musings - Printable Version +- Python Forum (https://python-forum.io) +-- Forum: Python Coding (https://python-forum.io/forum-7.html) +--- Forum: General Coding Help (https://python-forum.io/forum-8.html) +--- Thread: Just some Boolean values musings (/thread-21546.html) |
Just some Boolean values musings - newbieAuggie2019 - Oct-04-2019 Hi! This is not a question, but just some musings of mine on Boolean values ... that maybe are useful to some other newbies. I was learning about Boolean values and their use in conditions, and I didn't know that when used in conditions, 0, 0.0, and "" (the empty string) are considered 'False', while all other values are considered 'True'. I wanted to check the truth in that (no pun intended! ), so I made this little program: name1 = '' name2 = 0 name3 = 0.0 name4 = 6 name5 = 'John' if not name1: print('This means that name1 = "" (empty string) is considered False, \ so not name1 is considered True.') if name1: print('This means that name1 = "" (empty string) is considered True.') if not name2: print('This means that name2 = 0 is considered False, \ so not name2 is considered True.') if name2: print('This means that name2 = 0 is considered True.') if not name3: print('This means that name3 = 0.0 is considered False, \ so not name3 is considered True.') if name3: print('This means that name3 = 0.0 is considered True.') if not name4: print('This means that name4 = 6 is considered False, \ so not name4 is considered True.') if name4: print('This means that name4 = 6 is considered True.') if not name5: print("This means that name5 = 'John' is considered False, \ so not name5 = 'John' is considered True.") if name5: print("This means that name5 = 'John' is considered True.")producing the following self-explanatory output: Maybe it's helpful to other newbies.All the best, RE: Just some Boolean values musings - buran - Oct-04-2019 (Oct-04-2019, 04:34 AM)newbieAuggie2019 Wrote: 0, 0.0, and "" (the empty string) are considered 'False', while all other values are considered 'True'Technically the second part of this statement (my bold) is not 100% true - None and empty sequences and container types like list, tuple, dict, etc. are also evaluated Falsehttps://docs.python.org/3/library/stdtypes.html#truth RE: Just some Boolean values musings - newbieAuggie2019 - Oct-04-2019 (Oct-04-2019, 05:55 AM)buran Wrote:Another little bit that I've just learned!!! Thank you!(Oct-04-2019, 04:34 AM)newbieAuggie2019 Wrote: 0, 0.0, and "" (the empty string) are considered 'False', while all other values are considered 'True'Technically the second part of this statement (my bold) is not 100% true - It makes sense, as it seems to me that None , empty sequences and other empty container types like list, tuple, dict, etc. give me the same linguistic feeling as '0', '0.0' or an empty string.All the best, |