No error , No gain

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. What's the difference between the list methods append() and extend()? append: Appends object at the end. x = [1, 2, 3] x.append([4, 5]) print(x) gives you: [1, 2, 3, [4, 5]] extend: Extends list by appending elements from the iterable. x = [1, 2, ..

I have a DataFrame from Pandas: import pandas as pd inp = [{'c1':10, 'c2':100}, {'c1':11,'c2':110}, {'c1':12,'c2':120}] df = pd.DataFrame(inp) print df Output: c1 c2 0 10 100 1 11 110 2 12 120 Now I want to iterate over the rows of this frame. For every row I want to be able to access its elements (values in cells) by the name of the columns. For example: for row in df.rows: print row['c1'], row..

What's the best way of checking if an object property in JavaScript is undefined? The usual way to check if the value of a property is the special value undefined, is: if(o.myProperty === undefined) { alert("myProperty value is the special value `undefined`"); } To check if an object does not actually have such a property, and will therefore return undefined by default when you try and access it..

How can I add a column with a default value to an existing table in SQL Server 2000 / SQL Server 2005? Syntax: ALTER TABLE {TABLENAME} ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE} WITH VALUES Example: ALTER TABLE SomeTable ADD SomeCol Bit NULL --Or NOT NULL. CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated. D..

There have been several questions already posted with specific questions about dependency injection, such as when to use it and what frameworks are there for it. However, What is dependency injection and when/why should or shouldn't it be used? The best definition I've found so far is one by James Shore: "Dependency Injection" is a 25-dollar term for a 5-cent concept. [...] Dependency injection ..

Can I convert a string representing a boolean value (e.g., 'true', 'false') into a intrinsic type in JavaScript? I have a hidden form in HTML that is updated based upon a user's selection within a list. This form contains some fields which represent boolean values and are dynamically populated with an intrinsic boolean value. However, once this value is placed into the hidden input field it beco..

I'm trying to iterate over the words of a string. The string can be assumed to be composed of words separated by whitespace. Note that I'm not interested in C string functions or that kind of character manipulation/access. Also, please give precedence to elegance over efficiency in your answer. The best solution I have right now is: #include #include #include using namespace std; int main() { st..

I have the following code in Ruby. I want to convert this code into JavaScript. What is the equivalent code in JS? text =

When I want to prevent other event handlers from executing after a certain event is fired, I can use one of two techniques. I'll use jQuery in the examples, but this applies to plain-JS as well: 1. event.preventDefault() $('a').click(function (e) { // custom handling here e.preventDefault(); }); 2. return false $('a').click(function () { // custom handling here return false; }); Is there any sig..

I have a JavaScript object like the following: var p = { "p1": "value1", "p2": "value2", "p3": "value3" }; Now I want to loop through all p elements (p1, p2, p3...) And get their keys and values. How can I do that? I can modify the JavaScript object if necessary. My ultimate goal is to loop through some key value pairs and if possible I want to avoid using eval. You can use the for-in loop as sh..