loops - Ways to iterate over a list in Java - Stack Overflow In Java 8 we have multiple ways to iterate over collection classes Using Iterable forEach The collections that implement Iterable (for example all lists) now have forEach method We can use method-reference introduced in Java 8 Arrays asList(1,2,3,4) forEach(System out::println); Using Streams forEach and forEachOrdered
How to iterate over columns of a pandas dataframe If you care about performance, I have benchmarked some ways to iterate over columns If you just want the column names, fastest method is to iterate over df columns values-- 51% faster than df columns, 86% faster than df and a whopping 2500% faster than df items() Details are as below:
How can I iterate over rows in a Pandas DataFrame? How to iterate efficiently If you really have to iterate a Pandas DataFrame, you will probably want to avoid using iterrows() There are different methods, and the usual iterrows() is far from being the best `itertuples()`` can be 100 times faster In short: As a general rule, use df itertuples(name=None) In particular, when you have a fixed
How do I efficiently iterate over each entry in a Java Map? How to iterate over the entries of a Map - @ScArcher2 has answered that perfectly What is the order of iteration - if you are just using Map , then strictly speaking, there are no ordering guarantees
c# - How to iterate over a dictionary? - Stack Overflow The best answer is of course: Think, if you could use a more appropriate data structure than a dictionary if you plan to iterate over it- as Vikas Gupta mentioned already in the (beginning of the) discussion under the question But that discussion as this whole thread still lacks surprisingly good alternatives
How to loop over grouped Pandas dataframe? - Stack Overflow As mentioned above, groupby object splits a dataframe into dataframes by a key So you can loop over each grouped dataframe like any other dataframe See this answer for a comprehensive ways to iterate over a dataframe The most performant way is probably itertuples() Following is an example where a nested dictionary is created using a loop on
Iterating over dictionaries using for loops - Stack Overflow When you iterate through dictionaries using the for in -syntax, it always iterates over the keys (the values are accessible using dictionary[key]) To iterate over key-value pairs, use the following: for k,v in dict iteritems() in Python 2; for k,v in dict items() in Python 3
Loop through an array of strings in Bash? - Stack Overflow Note that the double quotes around "${arr[@]}" are really important Without them, the for loop will break up the array by substrings separated by any spaces within the strings instead of by whole string elements within the array ie: if you had declare -a arr=("element 1" "element 2" "element 3"), then for i in ${arr[@]} would mistakenly iterate 6 times since each string becomes 2 substrings