But be sure to test it yourself as well! In the example below, there is a function to calculate the variance of a list. However, I've seen that Java EE 6 has an annotation named @Id (see documentation), so it seems Java considers "Id" to be just a normal word. PEP 8 provides two options for the position of the closing brace in implied line continuations: Line up the closing brace with the first non-whitespace character of the previous line: Line up the closing brace with the first character of the line that starts the construct: You are free to chose which option you use. In Python, you can import that script as a module in another script. WebMost python people prefer underscores, but even I am using python since more than 5 years right now, I still do not like them. But why is readability so important? Example of int numbers include 0,100,10000000000, -5402342, and so on. Not contain special characters. WebcamelCase only to conform to pre-existing conventions As mentioned above, its pretty common to have all caps to represent constants. Why does RSASSA-PSS rely on full collision resistance whereas RSA-PSS only relies on target collision resistance? Daddy at Home. The following example is much clearer. Okay is the phonetic version of OK (from. Interested in a verified certificate or a professional certificate? Websnake_case variables, properties, and functions. But I highly would not recommend 'ID' all in CAPS because we generally use all caps for defining CONSTANTS. The most important place to avoid adding whitespace is at the end of a line. Another Real Python tutorial, Python Code Quality: Tools & Best Practices by Alexander van Tol, gives a thorough explanation of how to use these tools. But, as always, consistency is key, so try to stick to one of the above methods. Red frownies will indicate your program output something unexpected. Also the underscore_style is sometimes called snake_case. Pascal case is sometimes called the upper camel case. Telegram x = y = z = 0 print(x) print(y) print(z) Output. Write them for all public modules, functions, classes, and methods. Using CamelCase just because the core libraries of some language use it isn't consistency, but rather conformity. Heres an example: Here, the inline comment does give extra information. Torsion-free virtually free-by-cyclic groups. Naming with Underscores in Python | by Rachit Tayal - Medium Learn more about Stack Overflow the company, and our products. , Python, : , , , . The short answer to this question is never. How do you normalize coding style among multiple isolated developers? Put the """ that ends a multiline docstring on a line by itself: For one-line docstrings, keep the """ on the same line: For a more detailed article on documenting Python code, see Documenting Python Code: A Complete Guide by James Mertz. Wrong example. PEP 8 recommends that you always use 4 consecutive spaces to indicate indentation. Write a Python program to convert a given string to Snake case. to help the adopting to new people on the team, there is no need to invent the wheel yourself, you might get tooling support to check and refactor. A quadratic equation has the following form: There always two solutions to a quadratic equation: x_1 & x_2. Yep, even in php, function names are case insensitive. intermediate, Recommended Video Course: Writing Beautiful Pythonic Code With PEP 8. I don't mean underscore is bad, it depends on what you prefer! GitHub 542), How Intuit democratizes AI development across teams through reusability, We've added a "Necessary cookies only" option to the cookie consent popup. Not only your own choice matters here, but also the language and the libraries styles. The __name__ variable (two underscores before and after) is a special Python variable. From PEP 8: _single_leading_underscore: weak "internal use" indicator. Most upvoted and relevant comments will be first, .10x frAgile FullStuck Midend Devlooper, Python, Nim, Arch, OpenSource, EN|ES, Argentina, UTC-3, Atheist, WFH Nim Team Leader. Erm your own link says otherwise as OK stands for OLL KORRECT (and similar) and thus it is not an abbreviation. This is two-step problem, so I have indicated each step by leaving a blank line between them. The following example is not PEP 8 compliant: When using a hanging indent, add extra indentation to distinguish the continued line from code contained inside the function. Websensitive languages such as C, C++, Python, and Java, the trend has been to use camel-case style identifiers. In a file called camel.py, implement a program that prompts the user for the name of a variable in camel case and outputs the corresponding name in snake case. Otherwise, your code will not run. WebUsing leading underscores for functions in a module indicates it should not be imported from somewhere else. When doing so, it is intuitive to do this with a statement like the one below: The use of the equivalence operator, ==, is unnecessary here. Well, according to Microsoft, it might not be what you think: Acronyms differ from abbreviations in that an abbreviation shortens a single word. Though not every language has such a dominant style (C++ comes to mind). It is also not clear to someone less familiar with Python list slicing what you are trying to achieve: However, this is not as readable as using .startswith(): Similarly, the same principle applies when youre checking for suffixes. When you write Python code, you have to name a lot of things: variables, functions, classes, packages, and so on. I personally prefer underscores, but camel case doesn't take too long to get used to. Note that the sentence wraps to a new line to preserve the 79 character line limit: Sometimes, if the code is very technical, then it is necessary to use more than one paragraph in a block comment: If youre ever in doubt as to what comment type is suitable, then block comments are often the way to go. Besides the while statement just introduced, Python uses the usual flow control statements known from other languages, with some twists.. 4.1. if Statements. Can range from 0 to any number imaginable. Weband run python manage.py compilejsunderscorei18n which will bundle your html templates into one js file for each locale supporting i18 {% trans %} tags. In this example, all three of the variables ( x, y, and z) are assigned to the same memory location. are all examples of camel casing. Always try to use the most concise but descriptive names possible. you can use Snake Case or Camel Case the way you like it. Example: userId. Almost there! DEV Community A constructive and inclusive social network for software developers. Remember that variable names are case-sensitive. Its the dash or hyphenated case, so dashes are used instead of underscores (to-string instead of to_string). Heres what PEP 8 has to say about them: Below is an example of an inline comment: Sometimes, inline comments can seem necessary, but you can use better naming conventions instead. Variable names should start with a lowercase letter and use camel case notation (e.g. In Python, there are many different ways to perform the same action, so guidelines on which methods to chose are helpful. But imagine coming back to this code in a few days. Can patents be featured/explained in a youtube video i.e. This is a bit pedantic, but I've seen some people use Id as in: Is one of these a better name than the other? PEP 8, sometimes spelled PEP8 or PEP-8, is a document that provides guidelines and best practices on how to write Python code. For a longer acronym, you lower case the rest of the acronym, e.g. The following examples of list slices are valid: In summary, you should surround most operators with whitespace. WebCamelCase for class names. In the example below, I have defined a function db() that takes a single argument x and doubles it: At first glance, this could seem like a sensible choice. Therefore, if you are using Python 3, then these errors are issued automatically: You can write Python code with either tabs or spaces indicating indentation. Languages may have explicit style guides. single_trailing_underscore_: used by convention to avoid conflicts with Python keyword, e.g. Which is the conventional standard? Libraries may have ad-hoc naming, but you'd better take it into account as well. Separate paragraphs by a line containing a single. WebCAPITAL_CASE_WITH_UNDERSCORES for constants, which seem to be rarely used in JS anyway. WebIt depends on the programming language. Example: user_id. __name. There are two classes of tools that you can use to enforce PEP 8 compliance: linters and autoformatters. Python (the original implementation) is a C program. DEV Community 2016 - 2023. Facebook Limit the line length of comments and docstrings to 72 characters. For example, commonly used tokens in many languages such as toString, checkValidity, lineHeight, timestampToLocalDateTime, etc. [closed], The open-source game engine youve been waiting for: Godot (Ep. It has been popular for a long time to write C code with underscore separated variable names. Learn more about Stack Overflow the company, and our products. You can extend the rules in any way you like. Heres an Interactive Demo on the Nim Playground (click on RUN). It may also be confusing for collaborators. One reason: In some RDBMS, column name is insensitive about those cases. Code that consistently breaks after a binary operator is still PEP 8 compliant. # There are always two solutions to a quadratic equation, x_1 and x_2. If you have more experience writing Python code, then you may need to collaborate with others. These are: int: Integers or whole numbers. Has Microsoft lowered its Windows 11 eligibility criteria? I believe that more important than the way you name variables is to be consistent and stick with certain style during a project. Why did the Soviets not shoot down US spy satellites during the Cold War? As for typing, unfortunately the underscore style loses the case a bit: _ is not the most convenient symbol for typing, requires both hands to be involved. The most important is that you can read the variable name and it's meaning. Consistency? It depends on the programming language. You can use them to explain and document a specific block of code. Python will assume line continuation if code is contained within parentheses, brackets, or braces: If it is impossible to use implied continuation, then you can use backslashes to break lines instead: However, if you can use implied continuation, then you should do so. As we saw above, empty lists are evaluated as falsy in Python. The specifics don't really matter as If theres too much whitespace, then it can be difficult to visually combine related terms in a statement. How does a fan in a turbofan engine suck air in? snake_case each word is lowercase with underscores separating words. In general, library names should not use abbreviations. Do not separate words with underscores. WebSnake case is a naming convention in which a developer replaces spaces between words with an underscore. To help you to check consistency, you can add a -t flag when running Python 2 code from the command line. Weband run python manage.py compilejsunderscorei18n which will bundle your html templates into one js file for each locale supporting i18 {% trans %} tags. : pip install django-static-underscore-i18n This is because it allows you to have multiple files open next to one another, while also avoiding line wrapping. It avoids naming conflict with Python keywords. Reddit In your terminal, execute the below to submit your work. Use an uppercase single letter, word, or words. This convention is known as "snake case" (the other popular method is called camelCase, where capital letters are used to show where the words start). Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. If you want to check whether a list is empty, you might be tempted to check the length of the list. Connect and share knowledge within a single location that is structured and easy to search. Separate words with underscores to improve readability. Identifiers must start with a Letter (A-Z) or an underscore ("_"), followed by more letters or numbers. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? In proofreading, underscoring is a convention that says "set this text in italic type", traditionally used on manuscript or typescript as an instruction to the printer.Its use to add emphasis in modern documents is a deprecated practice. [closed], The open-source game engine youve been waiting for: Godot (Ep. Use grammatically correct variable names, the class name should start with an uppercase and must follow camelCase convention If more than two words are to be used. lowercase_with_underscores for methods, functions, variables and attributes. for everything related to Python's style guide: i'd recommend you read PEP8 . To answer your question: Function names should be lowercase, with wo The rules for variable naming in Python are simple: lowercase only; don't start with special characters - $, & separator is _ - underscore; avoid single character variables db() could easily be an abbreviation for double. Just agree on something and stick to it. (private, public, static etc.) PEP stands for Python Enhancement Proposal, and there are several of them. Posted on Jul 10, 2019 Also, it's correct to want to have the toilet paper roll from the top unless you have cats who get bored and do strange things, in which case they have much harder time unraveling the toilet paper set to roll from the bottom making such heresy acceptable for cat owners. Its good practice to leave only a single line between them: Use blank lines sparingly inside functions to show clear steps. Pascal Case (PascalCase) The interpreter will issue warnings when you are inconsistent with your use of tabs and spaces: If, instead, you use the -tt flag, the interpreter will issue errors instead of warnings, and your code will not run. I'm from Java/Dart background, I also had a similar question for python. Based on that, I'd say "ID" in Java, "Id" in C#. There are other cases where PEP 8 discourages adding extra whitespace, such as immediately inside brackets, as well as before commas and colons. The following example is difficult to read because the code inside the function is at the same indentation level as the continued lines: Instead, its better to use a double indent on the line continuation. And hence any approved standard can be used and followed during development. If you were trying to check if a string word was prefixed, or suffixed, with the word cat, it might seem sensible to use list slicing. Instagram Clubhouse Mathematicians agree that breaking before binary operators improves readability. Inline comments explain a single statement in a piece of code. Function names should be lowercase, with words separated by And because of that I think it does not matter if you use undercases or camel case. You could get away with only using block comments so, unless you are sure you need an inline comment, your code is more likely to be PEP 8 compliant if you stick to block comments. If you want to learn more about PEP 8, then you can read the full documentation, or visit pep8.org, which contains the same information but has been nicely formatted. In this section, youll see an outline of how the linters work, with links to the text editor extensions at the end. Note: When = is used to assign a default value to a function argument, do not surround it with spaces. But despite that I'm still in favour of snake case for better readability. mixedCase is allowed only in contexts where that's WebAmong these are three common identifier casing standards: camelCase each word is capitalized except the first word, with no intervening spaces. WebRules for Python variables: A variable name must start with a letter or the underscore character A variable name cannot start with a number A variable name can only contain I care about my sanity and yours too. In Pascal-cased identifiers they should appear as Id, and Ok. Why was the nose gear of Concorde located so far aft? Or that you want to import the functions defined in the script. And usually we dont use underscores when naming classes, so use a variation of camelcase with it. Thanks to this special variable, you can decide whether you want to run the script. From PEP 8: _single_leading_underscore: weak "internal use" indicator. kebab-case for CSS ids/classes. If there is not enough whitespace, then code can be difficult to read, as its all bunched together. It will become hidden in your post, but will still be visible via the comment's permalink. Names with a leading double underscore will only be used in special cases, as they makes subclassing difficult (such names are not easily seen by child classes). Youll also avoid using inappropriate names that might result in errors that are difficult to debug. Lets take a look at a Python example: myAccountBalance = 100 distanceToMoon = 3.844e8 2. Common loop variable names for indexes in 4D and above. When theres more than one operator in a statement, adding a single space before and after each operator can look confusing. Here is what you can do to flag prahladyeri: prahladyeri consistently posts content that violates DEV Community's The best way to name your objects in Python is to use descriptive names to make it clear what the object represents. Hence, its helpful to be aware of the conventions typical in various programming languages. Most object-oriented programming languages don't allow variable, method, class and function names to contain spaces. This totally depends upon mutual agreement by team members. Would the reflected sun's radiation melt ice in LEO? There is an entire PEP, PEP 257, that covers docstrings, but youll get a summary in this section. Otherwise, it can confuse the reader. Related Tutorial Categories: Pascal Case (ex: SomeVar, SomeClass, SomePackage.xyz ). WebUsing leading underscores for functions in a module indicates it should not be imported from somewhere else. Share Improve this answer Follow Can range from 0 to any number imaginable. Compare the following two examples. Is using uncommon words as descriptive variable names acceptable? Webvariables, functions, and classes. Use a lowercase word or words. Documentation strings, or docstrings, are strings enclosed in double (""") or single (''') quotation marks that appear on the first line of any function, class, method, or module. Are you sure you want to hide this comment? A general coding practice is to write code with variable names in English, as that is the most likely common language between programmers. I use ID becuase then it breaks the convention and stands out as being unique, and i like the irony of that :), I think Microsoft are wrong. Use grammatically correct variable names, the class name should start with an uppercase and must follow camelCase convention If more than two words are to be used. Some_Val is a mix of camel and underscores, its less popular and rarely used. Anecdotally, I'm not actually sure when this distinction started appearing in the guidelines, but a few years back (around 3.0 / 3.5) the general naming trend in class libraries went from ID to Id. camelCase is the typographical convention where a name is formed up of many words each having a capital letter at the start barring the first word eg. Camel case is the preferred convention in C#. What you refer to as camelCase is sometimes called lowerCamelCase and what you call PascalCase is sometimes called UpperCamelCase. Commenting Tips: The most useful comments are those written with the goal of learning from or helping out other students. Those with more training were quicker on identifiers in the camel case style. as much as possible in expressions in R. For example, I can name a variable n_years rather than n.years. It is invisible and can produce errors that are difficult to trace. As a beginner, following the rules of PEP 8 can make learning Python a much more pleasant task. to make a file called camel.py where youll write your program. PEP 8 outlines ways to allow statements to run over several lines. Do German ministers decide themselves how to vote in EU decisions or do they have to follow a government line? Variable names should start with a lowercase letter and use camel case notation (e.g. Should we prioritize being consistent throughput the project or sticking to the specific frameworks' conventions? If youre using Python 2 and have used a mixture of tabs and spaces to indent your code, you wont see errors when trying to run it. Consistency is king; pick one or the other, but do it consistently everywhere. For ex, mysqli::set_local_infile_default vs PDOStatement::debugDumpParams. WebA single underscore can also be used after a Python variable name. It is often used as a convention in variable declaration in many languages. The benefit of using this method is that the interpreter tells you where the inconsistencies are: Python 3 does not allow mixing of tabs and spaces. Anecdotally, I'm not actually sure when this distinction started appearing in the guidelines, but a few years back (around 3.0 / 3.5) the general naming trend in class libraries went from ID to Id. Youll often need to check if a Boolean value is True or False. Too much whitespace can make code overly sparse and difficult to follow. I hate technical debts, very much. If we're talking about C# or .NET class library conventions, Microsoft has some fairly well defined naming guidelines available. I was thinking why we should type 1 more "_", of course this will take very short time for 1 variable or 1 method, but we will have many of them in a program. Camel case combines words by capitalizing all words following the first word and removing the space, as follows: Raw: user login count. Reason for placing function type and method name on different lines in C, articles in variable names and hard-coding strings. But, if youre using Python 3, you must be consistent with your choice. This is slightly counter-intuitive, since it's a rare example of an abbreviation that is allowed / recommended (abbreviations are generally frowned upon). Each capital letter is begining of word. rev2023.3.1.43268. Names like main-div, main-navbar and article-footer are commonly used by web developers while writing their HTML/CSS. further to what @JohnTESlade has answered. Google's python style guide has some pretty neat recommendations, Names to Avoid single character name As @patrykrudnicki says, constants are handled differently. How are you going to put your newfound skills to use? Use 'Id' if naming a var without any Underscore to differentiate the different words. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, Order of subject and modifiers in variable names. Can also contain negative numbers within the same range. [A-Z])', r'\1_\2', sourceString).lower() ) # random_camel_case_variable_one random_camel_case_variable_two To learn more about Regular Expressions in Python, 'D recommend you read PEP8 resistance whereas RSA-PSS only relies on target collision resistance variation of CamelCase it. Subject and modifiers in variable names the following examples of list slices valid..., followed by more letters or numbers pretty common to have all for... To show clear steps case the rest of the above methods with it project sticking. Someclass, SomePackage.xyz ) write your program ( ex: SomeVar, SomeClass, SomePackage.xyz ) of that... One or the other, but do it consistently everywhere insensitive about those cases conventions, Microsoft has some well... Are difficult to debug 'd better take it into account as well most important is that want! 8 can make learning Python a much more pleasant task share Improve this follow... Main-Div, main-navbar and article-footer are commonly used tokens in many languages upon mutual agreement by members... You to check consistency, but camel case notation ( e.g x ) print ( )! To show clear steps must start with a lowercase letter and use camel case the way you it... Much as possible in expressions in R. for example, I 'd say `` Id in! Sure you want to check if a Boolean value is True or False if you have more experience python camelcase or underscore variables. Separating words hide this comment your program output something unexpected object-oriented programming languages to... Surround it with spaces popular and rarely used are those written with the goal of from... Or False you refer to as CamelCase is sometimes called the upper camel case does n't take too to... Libraries styles are always two solutions to a quadratic equation has the following examples of list slices are valid in! To one of the list CamelCase just because the core libraries of some language use it is not enough,.: Godot ( Ep 72 characters fairly well defined naming guidelines available and best on. A naming convention in C # start with a lowercase letter and use case. To stick to one of the above methods as CamelCase is sometimes called UpperCamelCase for methods, functions variables... On how to vote in EU decisions or do they have to follow a line... If we 're talking about C # much whitespace can make code overly sparse and difficult to trace programming. -T flag when running Python 2 code from the command line to conform to conventions. Heres an example: Here, the inline comment does give extra information and we... C # docstrings to 72 characters team members: int: python camelcase or underscore variables or whole.! Somewhere else will still be visible via the comment 's permalink: Here the... Consistency is king ; pick one or the other, but rather conformity practices on how write... And thus it is not enough whitespace, then code can be used and followed during development using 3... March 2nd, 2023 at 01:00 AM UTC ( March 1st, Order subject! Interactive Demo on the Nim Playground ( click on run ) can produce errors are! The command line name is insensitive about those cases visible via the comment 's permalink can the... Constants, which seem to be aware of the variables ( x y... Resistance whereas RSA-PSS only relies on target collision resistance during a project get a summary this... Contain spaces with it a module indicates it should not use abbreviations ( from and the libraries styles writing code... With spaces in many languages multiple isolated developers visible via the comment 's.... Problem, so use a variation of CamelCase with it PDOStatement::debugDumpParams Tayal - Medium Learn about... The functions defined in the example below, there are two classes of tools that you can use enforce. Each step by leaving a blank line between them: use blank lines sparingly inside functions to clear! In Java, the inline comment does give extra information with PEP 8 compliant engine suck in! Always, consistency is key, so guidelines on which methods to chose helpful... Import the functions defined in the example below, there is an entire,! To debug more important than the way you like it your post, but will still be visible the. Hard-Coding strings spy satellites during the Cold War to use camel-case style identifiers Mathematicians agree that breaking binary! Errors that are difficult to read, as its all bunched together then code be! ( to-string instead of underscores python camelcase or underscore variables to-string instead of underscores ( to-string instead underscores... Classes, and our products that provides guidelines and best practices on how to C. Just because the core libraries of some language use it is often used as a module indicates should. With underscore separated variable names mix of camel and underscores, its helpful to be rarely.! Webusing leading underscores for functions in a piece of code the company, and methods lines sparingly inside functions show. In various programming languages it yourself as well empty lists are evaluated as in... Camelcase just because the core libraries of some language use it is not enough,! Engine youve been waiting for: Godot ( Ep to_string ) multiple isolated developers any. By convention to avoid conflicts with Python keyword, python camelcase or underscore variables more letters or numbers and.. Names like main-div, main-navbar and article-footer are commonly used tokens in many.... Less popular and rarely used 8: _single_leading_underscore: weak `` internal use '' indicator have more writing... In caps because we generally use all caps to represent constants thanks to this code a. When theres more than one operator in a module indicates it should not be imported from else... Methods, functions, variables and attributes case or camel case does n't take too long to used. Over several lines it will become hidden in your terminal, execute the below to submit your work a.... Then you may need to collaborate with others note: when = is used assign! Such a dominant style ( C++ comes to mind ) and above writing Pythonic... Depends upon mutual agreement by team members the original implementation ) is a mix camel! For a longer acronym, you must be consistent with your choice a naming convention in variable names start. A statement, adding a single space before and after ) is a mix camel... 'S radiation melt ice in LEO with underscores separating words used as a convention C. Mentioned above, empty lists are evaluated as falsy in Python, and Java, the open-source game engine been... Allow statements to run over several lines reflected sun 's radiation melt ice in LEO include 0,100,10000000000 -5402342. Explain and document a specific block of code it will become hidden in your post but! Blank line between them: use blank lines sparingly inside functions to show clear steps sure to it. Same range or camel case style in which a developer replaces spaces between with... And methods many languages such as C, articles in variable names in English, as is... Be featured/explained in a youtube Video i.e does a fan in a module in another script strings... Rsassa-Pss rely on full collision resistance whereas RSA-PSS only relies on target collision resistance whereas RSA-PSS only relies on collision. Imported from somewhere else because the core libraries of some language use is! Webcamelcase only to conform to pre-existing conventions as mentioned above, empty python camelcase or underscore variables are as...: Here, but rather conformity names acceptable one or the other, but also the and... If we 're talking about C # or.NET class library conventions, Microsoft has some fairly well naming. Though not every language has such a dominant style ( C++ comes to mind ) so on why RSASSA-PSS.: in some RDBMS, column name is insensitive about those cases same.! Sparse and difficult to trace with an underscore spelled PEP8 or PEP-8, is a special variable.: _single_leading_underscore: weak `` internal use '' indicator: there always two solutions to a quadratic equation the! Enough whitespace, then code can be used and followed during development its good practice to only. Of tools that you can add a -t flag when running Python 2 from! # there are several of them: used by web developers while writing their.... Terminal, execute the below to submit your work look confusing libraries styles show clear steps read PEP8 to. A -t flag when running Python 2 code from the command line likely common language between programmers be... For software developers a document that provides guidelines and best practices on how to in... Pep-8, is a C program I can name a variable n_years rather than n.years mutual. Write Python code single location that is the phonetic version of OK ( from module in another script a. Practice is to be aware of the conventions typical in various programming do! Isolated developers letter and use camel case is sometimes called the upper camel notation., checkValidity, lineHeight, timestampToLocalDateTime, etc with underscore separated variable names should not be imported from else... Frownies will indicate your program sparse and difficult to follow a government line you 'd take. Choice matters Here, the open-source game engine youve been waiting for: Godot Ep. ) or an underscore ( `` _ '' ), followed by more letters or numbers for,! Breaking before binary operators improves readability represent constants different words will become in! Appear as Id, and methods two-step problem, so I have indicated each step by leaving a line. Bunched together `` internal use '' indicator approved standard can be difficult to.! And modifiers in variable names should start with a letter ( A-Z ) an!