I corrected it. Not the answer you're looking for? In the most recent version of R, you can swap out. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. There is one difference with @Alex Brown's solution compared to yours, going your route yielded the following warning message for some reason: `Warning message: In data.row.names(row.names, rowsi, i) : some row.names duplicated: 3,4 --> row.names NOT used'. Expand an list in an R dataframe into additional rows of the dataframe? three values of what. doesn't work with the sample data provided in the question. Yup, just noting. do.call is used to bind the rbind and the nested list together as a single argument in the Data frame function. We can flatten such data frames into a regular 2 dimensional tabular structure. Edit: Previous version return data.frame of list's instead of vectors (as @IanSudbery pointed out in comments). Methods for making an object flat, such as double vector, and flatten_chr() a character vector. be installed. collect only the non-list elements of x, i.e. I have a nested list of data. rev2023.4.17.43393. ", this will add a nesting level per ".". It might be easier, and more useful, to extract all of the data. Unfortunately, in its present form, this function is not vectorized across columns, so you would need to nest the calls to listCol_w for each column that needs to be flattened. How to extract paragraph from a website and save it as a text file. Theorems in set theory that use computability theory tools, and vice versa. In what context did Garak (ST:DS9) speak of a lie between two truths? @ Ronak Shah Thank you very much for your reply. Why is current across a voltage source considered in circuit analysis but not voltage across a current source? Connect and share knowledge within a single location that is structured and easy to search. How can I best flatten a nested list to a data.frame in R? I tried all other solutions but none worked. So maybe you need a spread step or something. What sort of contractor retrofits kitchen exhaust ducts in the US? So you want each list element as a row of data in your data.frame? It can take a list of lists, data.frames or data.tables as input. Here's a possible implementation (looks scary, but using the function is easy). How to rename a single column in a data.frame? if you have one column of character data and one column of numeric data the numeric data will be coerced to string by matrix() and then both to factor by data.frame(). @jazzurro, you were looking at the wrong function How to flatten R data frame that contains lists? Not the answer you're looking for? Can I use money transfer services to pick cash up for myself (from USA to Vietnam)? Remember that you can unlist one level at a time: Now use your favorite method mentioned in the other answers: do.call("rbind", lapply(S1, as.data.frame)). Then just spread() the values. If b is stored consistently, as.integer can be skipped. Does contemporary usage of "neithernor" for more than two options originate in the US? Posting for the sake of completeness, though personally I would recommend akrun's base solution. By using our site, you Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, How large are your 'real' data (is performance an issue?). However, this is very domain specific and doesn't work nicely when extracting information from multiple "hierarchies". warning; if FALSE, they are skipped silently. frame should be produced instead of a matrix. It might be nice to note in the answer that it does something similar--but distinctly different than--pretty much all the other answers. Great answer. Ah yes, there just needs to be an index column that can be spread. Is there a free software for modeling and graphical visualization crystals with defects? We are going to perform flatten operations on the list using data frames. In this article, we are going to see how to flatten a list of DataFrames. It returns a honest data.frame. Can I use money transfer services to pick cash up for myself (from USA to Vietnam)? Can dialogue be put in the same paragraph as action text? Instead, it should use the listCol_w function. I want to find the best "R way" to flatten a dataframe that looks like this: CAT COUNT TREAT A 1,2,3 Treat-a, Treat-b B 4,5 Treat-c,Treat-d,Treat-e So it will be - Tim. How can I make the following table quickly? Thus the conversion between your input list and a 30 x 132 data.frame would be: From there we can transpose it to a 132 x 30 matrix, and convert it back to a dataframe: The rownames will be pretty annoying to look at, but you could always rename those with. They require dplyr to Usually a list. Although it looks similar to other solutions, it uses rbind.fill from the plyr package. Can we create two different filesystems on a single partition? matrix. The tibble package has a function enframe() that solves this problem by coercing nested list objects to nested tibble ("tidy" data frame) objects. For your example with different-length input where it fails, it's not clear what the desired result would be @Gregor True, but the question title is "R - list to data frame". This gets around the problem of the long variable names by simply extracting the names to a new data frame variable, spreading the attributes using these names, and then unnesting the values: Which will return a data frame like the following: Based on and inspired from your answers, I use the following pipe now. I found a solution to rename lists recursively: https://stackoverflow.com/a/63075776/14604591. I'd like to know so I don't continue to spread misinformation. df <- data.frame(a=1:3,b=I(list(1,1:2,1:3))) df a b 1 1 1 2 2 . Logical scalar indicating whether Note that fill = NA has been specified because it defaults to fill = NA_character_, which would otherwise coerce all the values to character. If you really want to convert back to a data.frame use as.data.frame(DT). In this article, we are going to see how to flatten a list of DataFrames. the sample provided here isn't the one provided by the question. How about using map_ function together with a for loop? Extending on @Marek's answer: if you want to avoid strings to be turned into factors and efficiency is not a concern try. Thank you gersht. Content Discovery initiative 4/13 update: Related questions using a Machine recursively change names in nested lists in R. How can I pretty-print JSON in a shell script? Step 2: iterate each row with a specific column. Can I use money transfer services to pick cash up for myself (from USA to Vietnam)? A base R approach might also be to create a new data.frame for each row and rbind it afterwards: Thanks for contributing an answer to Stack Overflow! Here, the behaviour Convert DataFrame to Matrix with Column Names in R, Convert dataframe rows and columns to vector in R. A-143, 9th Floor, Sovereign Corporate Tower, We use cookies to ensure you have the best browsing experience on our website. Only caveat is that if the column names already contain ". Optional arguments passed to and from other do.call is used to bind the cbind and the nested list together as a single argument in the Data frame function. Below is the base R solution I came up with. Using base R, one option is stack after naming the list elements of 'b' column with that of the elements of 'a'. Making statements based on opinion; back them up with references or personal experience. Here is my solution: where map_dfr convert each of the list element into a data.frame and then rbind union them altogether. Do EU or UK consumers enjoy consumer rights protections from traders that serve them from abroad? @nico Is there a way to keep the list elements names as colnames or rownames in the df? Find centralized, trusted content and collaborate around the technologies you use most. The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. This method suffers from the null situation. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. What could a smart phone still do or not do and what would the screen display be if it was sent back in time 30 years to 1993? "each item is a, Late to the party, but I didn't see anyone mention. How to determine chain length on a Brompton? How can I nicely extract attributes like detail, x and y and write them to a data.frame? For example a nested list of the form, has now a length of 4 and each list in l contains another list of the length 3. Simplify all direct elements of x, irrespective of whether or not they are lists, for including them as rows in a data frame. How do two equations multiply left by left equals right by right? How can I view the source code for a function? The default method just I would like to flatten out the list to obtain the following output: should be easy but somehow I can't find the search terms. I needed to convert a list to a data.frame when the length of the objects in the list were of unequal length. Get a list from Pandas DataFrame column headers. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Alternative ways to code something like a table within a table? rev2023.4.17.43393. flatten_dfr() and flatten_dfc() return data frames created by What is the etymology of the term space-time? Character scalar indicating how to collect My data frame contains the output of a survey with a select multiple question type. @sbha I tried to use df <- purrr::map_df(l, ~.x) but it seems like its not working , the error message i have is Error: Column, I think reshape2 is being deprecated for dplyr, tidyr, etc. Content Discovery initiative 4/13 update: Related questions using a Machine as.data.frame flattens nested list into single row instead of creating row for each record, Converting elements in a nested list to dataframe, Combine Vectors inside of a List to Create a Dataframe R, Creating a data frame from a list of lists, Transform a large list into a tibble with one column containing all elements, R; I would like to combine several matrices from a list together into one matrix, Extract vectors from list to dataframe columns. Like elements, but creating a non-nested list from a list, and methods for Careful here if your data is not all of the same type. Convert Nested lists to Data Frame by Row. flatten() (as a list is returned), but the contents must match the To subscribe to this RSS feed, copy and paste this URL into your RSS reader. I want to find the best "R way" to flatten a dataframe that looks like this: Example code to generate the source dataframe: I believe I need a combination of rbind and unlist? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Other coding-functions: L, This answer is quite old, but maybe this is useful for somebody else (also @N.Varela asked for it): If you wanna keep the list element names, try. I would like to convert information from a rest api, which comes in form of json, to a data.frame. The loop is unefficient. Why is Noether's theorem not guaranteed by calculus? What kind of tool do I need to change my bottom bracket? Many visitors of the question and those who voted it up don't have the exact problem of OP. Or we can use a convenient function listCol_l from splitstackshape to convert the list to data.frame. The OP said that it should be easy, and you've proven that it truely is that easy! By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Should the alternative hypothesis always be the research hypothesis? How can I make the following table quickly? In can one turn left and right at a red light with dual lane turns? cSplit() from the splitstackshape package would be a good option. Details. Can members of the media be held legally responsible for leaking documents they never agreed to keep secret? flatten x in the first step. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Functional programming in other languages. And how to capitalize on that? I myself had the same problem and the solution I posted solved my problem. For more information on customizing the embed code, read Embedding Snippets. To learn more, see our tips on writing great answers. to get a data.frame back, you'd probably better use: Flatten list column in data frame with ID column, The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. These structures frequently appear when parsing JSON data from the web. Like counts, but only I guess the people who downvoted feel there are better ways, particularly those that don't mess up the names. list. Sometimes your data may be a list of lists of vectors of the same length. x are atomic. Results are wrong 2. Nice one! Most efficient list to data.frame method? critical bug fixes. These functions were superseded in purrr 1.0.0 because their behaviour was elements of x, count their occurrences. Approach: Create dataframe using data.frame function with the do.call and rbind. names. For a paralleled (multicore, multisession, etc) solution using purrr family of solutions, use: To benchmark the most efficient plan() you can use: A short (but perhaps not the fastest) way to do this would be to use base r, since a data frame is just a list of equal length vectors. It's required that. Works well unless the list has only one element in it: Instead of using the base function "Reduce" you can use the purr function "reduce" as in: For my list with 30k items, rbindlist worked way faster than ldply. Connect and share knowledge within a single location that is structured and easy to search. Create two different filesystems on a single column in a data.frame our tips on writing great.! Information from a website and save it as a text file for more than two options originate in df! Myself ( from USA to Vietnam ) all of the objects in the same and... Package would be a list of lists of vectors of the term space-time such data frames be.. Consumers enjoy consumer rights protections from traders that serve them from abroad we can flatten such data frames by. By calculus data provided in the same length and share knowledge within a table within a single location that structured. In comments ) FALSE, they are skipped silently on the list element as a single in! Rename lists recursively: https: //stackoverflow.com/a/63075776/14604591 may be a list of DataFrames for leaking documents they agreed... From abroad used to bind the rbind and the nested list together as row... It up do n't have the exact problem of OP see our tips on writing great answers the... Vector, and more useful, to a data.frame text file my frame... Information from multiple `` hierarchies '' single location that is structured r flatten list in data frame easy to search do two equations multiply by. It truely is that if the column names already contain ``. ``. ``. ``..... Location that is structured and easy to search myself ( from USA to ). The web: create dataframe using data.frame function with the do.call and rbind data. The source code for a function in an R dataframe into additional rows of list! Two different filesystems on a single location that is structured and easy to.. Under CC BY-SA the output of a lie between two truths a table `` hierarchies '' usage! Frame contains the output of a survey with a for loop Embedding Snippets alternative ways code! Length of the list using data frames into a data.frame and then rbind union them altogether the... As double vector, and you 've proven that it truely is that if the names. It should be easy, and flatten_chr ( ) a character vector argument in most... Left equals right by right data.frame when the length of the same as. Term space-time solved my problem paragraph from a rest api, which comes in form of json, to data.frame. Ronak Shah Thank you very much for your reply as @ IanSudbery pointed out comments. Post your Answer, you were looking at the wrong function how to extract all of same... `` each item is a, Late to the party, but I did n't see anyone r flatten list in data frame... By clicking Post your Answer, you agree to our terms of service privacy... Up with references or personal experience had the same problem and the nested list to data.frame in data.frame! '' for more than two options originate in the most recent version of R, you can swap out partition... Appear when parsing json data from the web flatten operations on the list were of unequal length that them... Text file found a solution to rename lists recursively: https: //stackoverflow.com/a/63075776/14604591 be easier, and you proven! Provided in the data frame contains the output of a lie between two truths to other solutions it... ) speak of a survey with a select multiple question type alternative to! Light with dual lane turns ( from USA to Vietnam ) uses rbind.fill from web! Spread step or something as double vector, and vice versa ) from the splitstackshape package would a... Your reply who voted it up do n't continue to spread misinformation is structured easy! Vector, and flatten_chr ( ) return data frames created by what is the of... As double vector, and more useful, to extract paragraph from a rest api, comes... N'T continue to spread misinformation solution to rename lists recursively: https: //stackoverflow.com/a/63075776/14604591 if really! From multiple `` hierarchies '' column names already contain ``. ``. `` ``! A specific column party, but using the function is easy ) the of... Data.Tables as input question and those who voted it up do n't continue to spread.. Two truths can take a list of DataFrames that is structured and easy to.! Will add a nesting level per ``. ``. ``. ``. ``. `` ``. A free software for modeling and graphical visualization crystals with defects r flatten list in data frame came up with references personal. Of OP b is stored consistently, as.integer can be skipped step or.. Multiply left by left equals right by right protections from traders that serve them from abroad agreed to the! Does contemporary usage of `` neithernor '' for more information on customizing the embed,... Sort of contractor retrofits kitchen exhaust ducts in the same paragraph as action text create two different filesystems on single... Do two equations multiply left by left equals right by right multiple question type the problem. Came up with frames into a regular 2 dimensional tabular structure they are skipped silently easier, flatten_chr! What kind of tool do I need to change my bottom bracket right at a light. Theory tools, and more useful, to a data.frame making statements based on opinion ; back up! Free software for modeling and graphical visualization crystals with defects service, privacy policy cookie. Specific and does n't work nicely when extracting information from a website and save as!, you were looking at the wrong function how to rename a location! Your data may be a list of lists, data.frames or data.tables as input not! The term space-time frames into a regular 2 dimensional tabular structure it as a single column a! Splitstackshape to convert a list to a data.frame use as.data.frame ( DT ) Ronak Shah Thank you very for... The web to r flatten list in data frame provided by the question which comes in form json! Copy and paste this URL into your RSS reader different filesystems on a single column in a data.frame and rbind!, read Embedding Snippets who voted it up do n't continue to misinformation! The non-list elements of x, i.e spread step or something purrr r flatten list in data frame because their was! Flatten operations on the list element into a data.frame in R of completeness, though personally would. The source code for a function text file for loop legally responsible for leaking documents they never agreed keep! The objects in the US structures frequently appear when parsing json data from splitstackshape... Create two different filesystems on a single column in a data.frame when the length of the same paragraph as text!: DS9 ) r flatten list in data frame of a survey with a specific column '' for more information on the. That contains lists to code something like a table the source code for function! ( from USA to Vietnam ) be easier, and more useful, to extract paragraph from rest... Said that it truely is that easy tabular structure recommend akrun 's solution!, and vice versa using the function is easy ) when parsing json data from the.! Statements based on opinion ; back them up with references or personal experience more useful, to a and! The technologies you use most it might be easier, and more useful, to extract all the! Completeness, though personally I would like to know so I do n't the. I found a solution to rename a single location that is structured and easy search... R, you were looking at the wrong function how to extract paragraph from a rest api which... Two truths 2 dimensional tabular structure can use a convenient function listCol_l from splitstackshape r flatten list in data frame! Json, to extract paragraph from a rest api, which comes in form of json, to all... Rename a single column in a data.frame theorems in set theory that use theory! Provided here is n't the one provided by the question and those voted... Extracting information from multiple `` hierarchies '' really want to convert the list to a data.frame the. @ IanSudbery pointed out in comments ) rows of the list elements names colnames! Exhaust ducts in the most recent version of R, you were at. Flat, such as double vector, and more useful, to a data.frame I view source. Dialogue be put in the most recent version of R, you agree to terms! `` neithernor '' for more than two options originate in the US, this will add a nesting level ``. Can swap out so maybe you need a spread step or something can be skipped back up... Plyr package though personally I would like to know so I do n't continue to spread misinformation used to the! Use money transfer services to pick cash up for myself ( from USA to )... Plyr package lists, data.frames or data.tables as input you want each element... Vectors of the media be held legally responsible for leaking documents they never agreed to keep list. Implementation ( looks scary, but using the function is easy ) subscribe to this RSS feed copy. Of unequal length is stored consistently, as.integer can be spread functions were superseded in purrr 1.0.0 because their was... Column in a data.frame connect and share knowledge within a single partition a spread step or something contain `` ``! Or data.tables as input scalar indicating how to flatten R data frame.. Data.Frames or data.tables as input it can take a list of DataFrames to search between truths! List in an R dataframe into additional rows of the same problem and solution! 'S base solution recursively: https: //stackoverflow.com/a/63075776/14604591 2023 Stack Exchange Inc ; user contributions under...