The condition (c != ‘o’ || c != ‘x’) can never be false. If c is ‘o’, then c != ‘x’ will be true and the OR condition is satisfied. If c is ‘x’, then c != ‘o’ will be true and the OR condition is satisfied. You want && (AND), not || (OR): while … Read more
It’s more useful for loops than if statements. while( var = GetNext() ) { …do something with var } Which would otherwise have to be written var = GetNext(); while( var ) { …do something var = GetNext(); }
Think of ! (negation operator) as “not”, || (boolean-or operator) as “or” and && (boolean-and operator) as “and”. See Operators and Operator Precedence. Thus: if(!(a || b)) { // means neither a nor b } However, using De Morgan’s Law, it could be written as: if(!a && !b) { // is not a and is … Read more
I think both the fastest and most concise way to do this is to use NumPy’s built-in Fancy indexing. If you have an ndarray named arr, you can replace all elements >255 with a value x as follows: arr[arr > 255] = x I ran this on my machine with a 500 x 500 random … Read more
Use Query::matching() or Query::innerJoinWith() When querying from the Contacts table, then what you are looking for is Query::matching() or Query::innerJoinWith(), not (only) Query::contain(). Note that innerJoinWith() is usually preferred in order to avoid problems with strict grouping, as matching() will add the fields of the association to the select list, which can cause problems as … Read more
You need to code your tests differently: if (number==1 || number==2 || number==3) { cout << “Your number was 1, 2, or 3.” << endl; } else if (number==4 || number==5 || number==6) { cout << “Your number was 4, 5, or 6.” << endl; } else { cout << “Your number was above 6.” … Read more
Instead of trim_end_matches (previously called trim_right_matches), I’d recommend using trim_end (previously called trim_right) or even better, just trim: use std::io; fn main() { let mut correct_name = String::new(); io::stdin() .read_line(&mut correct_name) .expect(“Failed to read line”); let correct_name = correct_name.trim(); if correct_name == “y” { println!(“matched y!”); } else if correct_name == “n” { println!(“matched n!”); … Read more
.ix indexer works okay for pandas version prior to 0.20.0, but since pandas 0.20.0, the .ix indexer is deprecated, so you should avoid using it. Instead, you can use .loc or iloc indexers. You can solve this problem by: mask = df.my_channel > 20000 column_name=”my_channel” df.loc[mask, column_name] = 0 Or, in one line, df.loc[df.my_channel > … Read more
Ruby uses the case expression instead. case x when 1..5 “It’s between 1 and 5” when 6 “It’s 6” when “foo”, “bar” “It’s either foo or bar” when String “You passed a string” else “You gave me #{x} — I have no idea what to do with that.” end Ruby compares the object in the … Read more
Are you asking something like the following? Let’s say your initial dataframe is df, which is the following: df A B C 1 2016-02-16 2016-03-21 2016-01-01 2 2016-07-07 2016-06-17 2016-01-31 3 2016-05-19 2016-09-10 2016-03-01 4 2016-01-14 2016-08-21 2016-04-01 5 2016-09-02 2016-06-15 2016-05-01 6 2016-05-09 2016-07-17 2016-05-31 7 2016-06-13 2016-06-23 2016-07-01 8 2016-09-17 2016-03-11 2016-07-31 9 … Read more