Pandas dynamic column name. Each column is named differently, say A, B, C etc.

Pandas dynamic column name DataFrame. loc[org_dataframe['month'] == i] i=i+1 It gives me, SyntaxError: can't assign to operator. rename(columns=dict(zip(df, new))) x098 y765 z432 0 1 3 5 1 2 4 6 This works great if your original column names are unique. Let's learn how to add column names to DataFrames in Pandas. val+10) Which gives me this output. pivot_table() or . In this tutorial we will explore four scenarios in which you can apply different transformations to all Data Frame columns simultaneously. An efficient way to create a DataFrame is by leveraging the date_range function, which allows you to generate a range of dates for indexing. join for sticker_value). Adding Column Names Directly to columns Attribute The simplest way to add column names is by directly assigning a list of co May 19, 2021 · In my excel file header start from D5 and row star from D6. plot: df. When I look up anything on dynamic naming in python, they say, don't do it, use a dictionary. A Series does not have columns (axis 1) - only an index (axis 0). csv') as f: num_cols = max(len(line. I don't know how many columns there will be, so I need this to be dynamic. mean()-df[readFromColName] works fine, but I was looking for a way to speed up the calculations. df = Oct 20, 2022 · Pandas aggregate with dynamic column names. I don't know if Pandas allows for it, but ideally, one would want to create exact n number of columns for each row, where n is the number of elements in column val. how do I create a dynamic string variable/name of dataframe. 1" so as to avoid duplicate names. I can't figure out how to replace X with [COL_NAME]_book_sticker_ids and Y with [COL_NAME]_sticker_values for each group in sticker_name column. Feb 20, 2024 · This method allows for renaming specific columns by passing a dictionary where keys are current column names and values are new column names. So I need: 1) identify all the Dec 8, 2023 · Sometimes, Pandas DataFrames are created without column names, or with generic default names (like 0, 1, 2, etc. Sep 15, 2015 · I want to subset each of these data frames and put them in a new data frame with a dynamic name. assign(col=lambda x: x. Nov 21, 2022 · The Python visualisation will automatically name the selected column to be summed columnname+". In the below screenshot, the yellow columns are the columns which i have to create dynamically based on response in other columns. How do I create dynamic variable names inside a loop in pandas. column_name). Jul 5, 2022 · To un-pivot, I would need to call column names, but they would keep changing every month; hence, I cannot use column names because of their dynamic nature. the problem is that if I have more than 1 row in the data framei cannot run this code since it returns only the first row does my question make sense. How to add a name to a Apr 5, 2019 · The Pandas dataframe data gets a new column Predicted Order in the dataframe whose values are assigned to the list predicted_order. ). be represented (and added to table) purely as strings, and tables be created dynamically with different column names (the strings coming from some other function or even user input etc. Here we dynamically create three columns that multiply the column A in our dataframe by each of the numbers in the list "multipliers". Feb 21, 2014 · I am attempting to dynamically create a new column based on the values of another column. If the value of column B is 1, insert 'Y' else insert 'N'. All the columns can be strings. With. apply(lambda s: dfx. The name of a Series becomes its index or column name if it is used to form a DataFrame. The following steps can be done to create a dataframe at runtime. A + df1. set_index('Name'). pop(0) if column_name in renamer else column_name ) a b_0 b_1 b_2 b_3 c_0 c_1 d Item 0 2 1 0 2 8 3 9 5 Item 1 3 2 7 3 5 4 6 2 Item 2 4 3 8 1 5 7 4 4 Item 3 5 5 3 6 0 5 2 5 Sep 17, 2015 · I would like to go through all the columns in a dataframe and rename (or map) columns if they contain certain strings. 1. split(',') and pass it under . column data type displayed in D4 cell onwards. If you want to iterate the columns, I'd suggest: for series in (df. I manage to get the result I wanted using this code: Most of these answers are going via the column name, rather than iterating the columns directly. col_name) but just know this trick to access the column names with space by using df[column name with space"]. My issue is that the name of the new column is assigned as keyword, so it cannot have spaces or dashes in it. DataFrame(data, columns=['ID', 'Name', 'Age']) # Renaming columns using the rename() method df. The simplest way to rename columns in a Pandas DataFrame is to use the rename() function. get_loc('C')]) total Sep 29, 2016 · I recently discovered pandas &quot;assign&quot; method which I find very elegant. I could come up with following. reindex(columns=list_of_cols_after_split) Sample data from different Data Sources Sample data in Excel, CSV, MySQL dump, SQLite databae, Pandas DataFrame → Number of columns to display When we collect data from the source ( database table or Excel or CSV file ) we are not sure how many columns will be available. Instead you can use the original DataFrame: dfx. DataFrame(lst,columns = ['name','val']) I only want to use pandas assign function to do the bellow task. Use a for loop to find the duplicated column name. Jun 4, 2015 · Created names might easily conflict with variables already used by your logic. shape[1])): You can change this to a column by passing the kwarg axis=1 to apply. 25, you can wrap your column name in backticks so this works: Filtering a dataframe on dynamic columns and values Python Pandas? Nov 4, 2017 · Create new dataframe in pandas with dynamic names also add new column. The resulting dataframe should looks like so: A|B|C 11|1|Y 22|0|N 33|1|Y 44|1|Y 55|0|N 4. This not only is simple and clear but also allows for fluent code readability when chaining methods. Create the source dataframe with some random values. pd. eval with the following expression: pd. Column C. Change column names dynamically. This guide provides a step-by-step solution to a common iss Jul 19, 2023 · It is a structure that contains named rows and columns, on which arithmetic operations can be aligned. 2. Use the list function in python to get a list of all column names. ), that I can later access with strings as well? Dec 6, 2018 · Now, I need to evaluate the change in price for every period of 251 days (Price251/Price1; Price252/Price2; Price 253/Price and so on) for each one of the companies, and create a column for each one of them. Email. Jan 2, 2025 · In this article, we will see how to rename column in Pandas DataFrame. Because some rows have less participants so it puts NaN which you can later fill with empty strings. Here is my solution so far for column 3 to 50. 5. plot() Output: For bar chart: df. Creating a new column name based on a loop variable and an Aug 4, 2022 · #select column with name 'spurs' df. plot. Create columns in python data frame based on existing column-name and column Apr 28, 2021 · How can I create dynamic column names in Pandas? 0. Another other major difference is how columns are accessed. Used database for demonstration: So, our student table has 5 columns namely sno, name, dob, class, and section, and our task is to fetch all these column names in our Python code. Typical column creation would be: df['new']=(df['one']*x)+(df['two']*y)+(df['3']*z) where x,y,z are variables from another df. assign(new_column=other_df['Column1']. Here, we split each column name on _ and use the second string as our new name for that column. itertuples(index=False): result += max(row[df. loc[] as shown above. Python Filter Dataframe with Dynamic arguments. columns, axis=1) returns. A variable can be used as the column name in a pandas query by inserting it into the query string like so: Nov 28, 2024 · Sometimes, Pandas DataFrames are created without column names, or with generic default names (like 0, 1, 2, etc. # Given just a list of new column names df. 0. Dynamically means by names. # Col. get_loc('B')], row[df. e. This method is great when df. s. Thx. – Jan 13, 2025 · Method 2: Accessing a Single Column Using Dot Notation. My new column name is a variable and I cannot hardcode it. read_csv(f, names=range(num_cols)) but the down side is that the file is Aug 14, 2021 · In this article, we are going to see how to dynamically get the column names of a table in SQLAlchemy using Python. I would also like to put the column name dynamic, so I can replicate this to a much longer database. Before deep diving into the scenarios lets import pandas library and create a Data Frame named df with the following column names: Mar 14, 2020 · I want to rename column 0 to 'Name', column 1 to Country and the rest to Group 1, Group 2 and so on. A B C 2011-01-10 A B C 2011-01-10 A B C 2011-01-11 A B C I am looking to create a column in a pandas dataframe that is the function of a variable/dynamic list of column names. Is there a better way to manipulate column names in a pandas dataframe? 0. col = 'val' df1 = df1. Apr 11, 2018 · Credit and thanks to user @choldgraf. One intuitive approach to assign a column name to a pandas Series is by setting the name attribute directly. This method allows renaming specific columns by passing a dictionary, where keys are the old column names and values are the new column nam Oct 5, 2021 · So one row per study_id, the text before each colon in the fuzzy_market column as the column title, and the text after each colon as the data in the cell. I don't want that, I want value of id in fld as the column and the text inside datVl as the value. create dynamically dataframes. the accepted answer shows "how to update column line_race to 0. Nov 18, 2024 · In this article, we will see how to rename column in Pandas DataFrame. Returns the new DynamicFrame. If the max number of fields isn't known in advance, you can dynamically extract by reading the file beforehand via with open('my. This is why dicts were included in the language. Python Pandas Dynamically Create a Dataframe. values) The problem is that, I am getting a new column named new_column. query('Name == "Total"'). columns attribute is reassigned to a new list of column names, effectively renaming all the columns in the dataframe. bar() Output: A minimum complete example: May 2, 2023 · Below i am trying to mention my requirement. 2\\nS1. name [source] # Return the name of the Series. Series. This is a more concise and readable approach but can only be used when the column name is a valid Python attribute. Aug 28, 2021 · This code sets the Name and Age columns as the index and stacks the rest of the columns Math and English, and resets the index and assigns Grade as the column name, then renames the other column level_2 to Subject and then sorts by the Subject column, then finally resets the index again. Since the names are dynamically created, you typically also end up using dynamic techniques to retrieve the data. Example 2: Select Multiple Columns by Name Aug 13, 2020 · lst = [['James',15],['Michael',10]] df1 = pd. iloc[:,i] for i in range(df. columns. filter to select the subset of the dataframe with the columns following the format of valx, aggregate with the mean, and then assign new columns with the aggregated results on the other columns: Nov 7, 2016 · Now, I want to add an extra column based on existing column. It is also used whenever displaying the Series using the interpreter. Here is the desired output: Jun 6, 2023 · #python PSA Sometimes, you need to dynamically create columns in pandas DataFrame, say in a post processing step. For example: rename all columns that contain 'agriculture' with the string 'a Oct 28, 2018 · Numbers separated by commas in column val need to represented in different columns for each row. name val 0 James 25 1 Michael 20 I want to May 6, 2018 · How to compare column names of 2 different Pandas data frame. You can use this access only if the index element is a valid python identifier, e. The incremented value would then be used inside the fstring to generate a new column name. Aug 5, 2022 · Getting column name are dividing in 2 sections. What I expect is a column named my_new_column_name Aug 28, 2019 · Pandas - Dynamic Column Names. iteritems(): # do something However, I don't really understand the use case. DataFrame() I am trying to have the value of 10 in the column name changed dynamically from another variable called date. eval("df1. In this guide, we’ll walk you through the steps to derive produc Discover how to dynamically create column names in a Pandas DataFrame based on entity categories. Dots Col. Description:Welcome to PowerBIisMyHobby!!! In this Power BI tutorial, we're going to explore a powerful technique to make your reports more flexible and inte pandas. DataFrame({'A':[1,2,3], May 29, 2020 · You can use pandas plot, first filter the dataframe down to just the total line then set_index and transpose, T, the dataframe rows and columns, then use pd. The correct way to proceed is: d = {} for name in companies: d[name] = pd. You could just iterate over the column names directly: for column in df. s="A,B,C", then split like: s. The Pandas dataframe set_axis() method can be used to rename a dataframe’s columns by passing a list of all columns with their new names. seek(0); df = pd. If you want in a new column name then condition should be unique because it will only give 1 col name for each row. Jul 15, 2017 · I need to create a set to 4 another dataframe. The key is specifying the column names directly in the DataFrame constructor through the columns argument, using the first row of our list of lists as the source for these names. Required, but never shown Post Your Answer Pandas df set dynamic column values by filtered rows. Instead of mentioning the columns names each time in groupby. Q1_SL should be set as 1 only in case all the three columns have same response else will be set as 0. 3 a 1. This method allows renaming specific columns by passing a dictionary, where keys are the old column names and values are the new column names. I was thinking of renaming the first 2 columns manually as I cannot come with a better way to do within the loop. Below is an example where you have to derive value to be updated with: Mar 5, 2024 · The entire DataFrame. It can be 0,1 or 0,2,3 or 1,2,3 anything. DataFrame({dynamic_column_name: [1, 2, 3]}) Description: Creates a DataFrame with a dynamic column name. In addition to bracket notation, you can also access columns using dot notation (df. I have a list which consist of indices of participating columns. Feb 29, 2020 · I have a Pandas dataframe df with 102 columns. name# property Series. – theteddyboy Sep 11, 2017 · I have a pandas dataframe structured like: >>> df Col1 Col. After constructing the dictionary columnnames with the original and new column names we will then passing the dictionary to the rename method Code: Dec 5, 2016 · There is a more easy way to accomplish this using exec method. "Python create dataframe with dynamic column name" Code Implementation: dynamic_column_name = "new_column" df = pd. Nov 26, 2020 · How can I create dynamic column names in Pandas? 0. Something like this. For example, to add two columns "A" and "B" in df1, you would call pd. i=1 while i<=4: dataframe+str(i)=org_dataframe. For each trimmed column name, look up the value in the first row of that column (which should give you a list of 5 different strings, which will be the new column names). in sql language what I am ultimately trying to Nov 25, 2017 · You are already getting to column name, so if you just want to drop the series you can just use the throwaway _ variable when starting the loop. Adding Column Names Directly to columns Attribute The simplest way to add column names is by directly assigning a list of co Oct 16, 2020 · Question is, how can I provide the pandas column name dynamically to the calc function as an argument on my apply (instead of explicitly mentioning 'AMOUNT' as in this case)? Thanks. for column_name, _ in df. new_column = "my_new_column_name" df = df. I used the technique he mentioned in another post (Unable to query a local variable in pandas 0. I want to compare train and test data frames where there are some columns missing in test Data frames?? Iterate over (column name, Series) pairs. T. Here, I don't want to hard code the newly generated column name, now it's Predicted Order. Create Dataframe Columns Automatically with Different Names. Method 2: Use Pandas set_axis() function to rename column names. . rename( columns=lambda column_name: renamer[column_name]. My dataset is big and above Jun 17, 2022 · I have a function I use to make duplicate rows in Pandas in order to have in each row a different value that were together before GRI_Code ADX_Code 102 S1. Method 3: Renaming Columns Using List Comprehension. I want every newly generated column takes name dynamically like this Week_i for i = 0,1,2 etc. Jun 17, 2022 · It take sthe attributes in each row as columns. eval looked promising and worked well for non-dynamic column names, but couldn't get it running when the column names where read from string. Say I have the following dataframe. 4 b 1. The original and new column names will be added to the dictionary as key, value pairs in every iteration. Returns: label (hashable object) The name of the Series, also the column name if part of a DataFrame. May 23, 2017 · pd. Using lists of column names and a category mapping dictionary, I was able to get my desired result. "Pandas dynamic dataframe name from list" Code Implementation: Jan 27, 2020 · In that case you can split the input on comma and create a list. I want to create a new column. Nov 12, 2021 · You could run one apply() which will use for-loop to convert list to Series with headers - it can use enumerate to put correct number in headers. g. eval, you need only supply the column names: df1. groupby([ 'Domain','Tag_Name', 'Tag_hierarchy', 'html_attributes']) I want to select columns dynamically for doing groupby. Feb 21, 2024 · The rename() method offers a flexible way to rename specific columns via a dictionary, without changing the entire structure. Both of these solutions output: Mar 25, 2021 · create dynamic column names in pandas. columns attribute, . 2 z 1. Aug 1, 2016 · How to create dynamic columns from this pandas dataframe. For example the following code does not work. Same logic needs to be applied for Q2_SL. 1 is not allowed. i want skip data type row and first blank columns A,B,C and Read Actual excel data using python pandas. x 1. split(',')) for line in f); f. Q1_SL is corresponding to Q1_1, Q1_2, and Q1_3. Method 1: Using the name Attribute. For example if date = 4, column name should be Count of sales done in the past 4 days and so on. . B") With df. In-place Renaming. Feb 19, 2024 · Summarizing DataFrames in Pandas Pandas DataFrame Data Types DataFrame to NumPy Conversion Inspect DataFrame Axes Counting Rows & Columns in Pandas Count Elements & Dimensions in DF Check Empty DataFrame in Pandas Managing Duplicate Labels in DF Pandas: Casting DataFrame Types Guide to pandas convert_dtypes() pandas infer_objects() Explained Oct 18, 2019 · Is there a way in pandas to apply a function to a dataframe using the column names as argument names? For example, I have a function and a dataframe. 14. The way I'd do this is using DataFrame. I can't quite figure out how to make it work though. The simplest way to add column names is by directly assigning a list of column names to the columns attribute of a DataFrame. 6 Feb 22, 2024 · This method offers a more streamlined approach to DataFrame creation with column names. To create a dataframe, the below syntax can be used: pd. eval("A + B") Since, within the context of df1, it is clear that "A" and "B" refer to column names. DataFrame(data, index, columns, dtypye, copy) In this example both the values in the columns and the column names are created dynamically. I do not know how to do it dynamically as in each iteration I need to save with different name. Dec 12, 2022 · Is there any way to make the column names in SQL-alchemy dynamic, i. So each time I update the Dataframe I want the value assigned to the variable date be shown in the column name. Any help would be much Nov 12, 2024 · In this article, we will see how to rename column in Pandas DataFrame. 0) not for the value in the column but for the column name. start_time = time. df = pd. 5 c 1. A|B 11|1 22|0 33|1 44|1 55|0. Where there is no relevant data for a column, I'd like to fill it with None. Firs Oct 31, 2017 · I have 3 datasets which need to be read and then do some calculation on some columns and makes a new columns, finally I have to save new columns in a new csv file. The Jul 2, 2020 · many thanks @cs95 - yes I should have been clearer - df[readFromColName]. 6. But if they are not, then this breaks down. df1['combined'] = df1['City']+','+df1['State'] Putting index doesn't seem to work. Feb 2, 2018 · I want to create percentage change column for each column that is a float in my dataframe and stored it in a newn column each time with the name of the initial column and the add on "_change" I From pandas 0. 1 y 1. Essentially I want the following: foo_first = foo[0:1] bar_first = bar[0:1] Aug 28, 2017 · I think you need [] for select column by column name what is general solution for selecting columns, because select by attributes have many exceptions:. agg() with dynamic column names (sticker_name) and different functions (list for book_sticker_id and '||. loc [:, ' spurs '] 0 10 1 12 2 14 3 13 4 13 5 19 6 22 Name: spurs, dtype: int64 Only the values from the ‘spurs’ column are returned. Sep 19, 2018 · Create new dataframe in pandas with dynamic names also add new column. Oct 21, 2019 · Dynamic Column Data In Pandas Dataframe (Populated By Dataframe) Ask Question Asked 5 years, 5 months ago. Adding Column Names Directly to columns Attribute . name val col 0 James 25 35 1 Michael 20 30 But i actually want this. Can the columns of a data frame be named based on the values of specific rows in python? 0. To rename columns based on some pattern or rule, list comprehension combined with attribute assignment can be used effectively. Each column is named differently, say A, B, C etc. Notes The column names will be renamed to positional names if they are invalid Python identifiers, repeated, or start with an underscore. keys() method, and converting to lists or NumPy arrays. import pandas as pd # Assuming df is defined earlier as shown in previous examples data = [ [1, 'John Doe', 30], [2, 'Jane Doe', 25] ] df = pd. DataFrame(results. columns: # do something Dec 17, 2022 · Name. Mar 9, 2021 · I can't find a way to use . 2 102\\n40 Jan 20, 2019 · As I would like to create a new column with the SUM of all columns between META and %, I need to get all the names of each column, so I can create something like that: a = df['Total'] = df['A'] + df['B'] + df['C'] + df['D'] + df['E'] As the columns name changes, the code below will work just for the example 1). This creates column names from values. def calc(row): factor = 3 h_value = int(row['AMOUNT']) // 100 output = h_value * factor return output The following takes advantage of the fact that when iterating over df, we iterate over each column name. Creating new pandas dataframe in each loop iteration. A DynamicRecord represents a logical record in a DynamicFrame. T,columns=['fixed_1','fixed_2'] + dynamic_list) This works as follows: list1 = ['a', 'b'] list2 = ['c', 'd'] list1 + list2 #['a', 'b', 'c', 'd'] Discover how to dynamically create new columns based on grouped data in Pandas using Python. % 0 text 111 111 111 1 text 222 222 222 2 text 333 333 333 3 text 444 444 444 4 text 555 555 555 Sep 20, 2017 · So I added line DF ["Name"] =i within the loop since I wanted to have a column in a data frame which says A for DF_A and B for DF_B. Sep 18, 2019 · Groupby. If you wish to modify the original DataFrame directly, you can use the inplace=True parameter: df. I have always used method given in Selected answer, today I faced a need where I need to Update column A, conditionally with derived values. to give the original dataframe following structure Column A. BDW you should be able to handle cases where user inputs a column which is not there in the dataframe, in such cases use df. Sep 16, 2019 · I want to add a new column in a dataframe with values from some other dataframe. 1\\nS5. How to efficiently update the column names in a pandas Jan 25, 2019 · I have a directory containing around 96 CSV files each containing a variable number of columns in range of [19000 to 23088]. That column is to be plotted as the Y Axis. Nov 28, 2024 · Let’s learn how to add column names to DataFrames in Pandas. I am trying to open each of the 96 files and copy the first row from the Feb 19, 2024 · This article demonstrates multiple ways to set or change the column name in a pandas Series. I am looping over and hope to assign name of dataframe dynamicall inside loop, like. Feb 22, 2022 · How can I create dynamic column names in Pandas? 0. Name, Sex a, M b, F c, M d, F Expected dataframe: Name, M, F a, 1, 0 b, 0, 1 c, 1, 0 d, 0, 1 I have tried pandas. Column B. Use a list of column names in groupby agg? 0. Nov 2, 2022 · Pandas - Dynamic Column Names. clock() result = 0 for row in df. Mar 6, 2013 · What fixed it for me was names=my_cols where my_cols was at least as long as the line with the most fields. They will also have issues if there are multiple columns with the same name. Jan 18, 2017 · I normally use dot to access my columns (df. how to set column names for groupby result. This method allows renaming specific columns by passing a dictionary, where keys are the old column names and values are the new column nam I want to create a function that adds a categorizing column for each abc column that exists in the dataframe. rename(columns={'Name': 'Full Name', 'City': 'City of Residence'}, inplace=True) print(df) Finally, the named itertuples() is slower than the previous point, but you do not have to define a variable per column and it works with column names such as My Col-Name is very Strange. rename(columns={'ID': 'UserId May 18, 2018 · I can do groupby on the dataframe by mentioning the column names as input to groupby: Example: Incoming_Tags. Here is an example of the table: I need to un-pivot these date columns and I cannot call column names as these columns may change next month. pivot() but of no use, could you guys suggest something. Mar 26, 2020 · For each column name, trim " Value" from the end (which should give you a list of 5 different strings, all of which should be names of columns in your table). I need to create it dynamically. fromDF(dataframe, glue_ctx, name) Converts a DataFrame to a DynamicFrame by converting DataFrame fields to DynamicRecord fields. The usual syntax of df['new column'] = <your stuff> ends up throwing annoying Dec 5, 2024 · Practical Examples of Creating and Filling Pandas DataFrames Example 1: Using date_range for Indexing. Dec 4, 2023 · Rename and Modify Column in Pandas DataFrame , the below code involves the creation of a Pandas DataFrame, initial display, renaming of columns, and subsequent modification with a second set of column names, followed by the final display of the modified DataFrame. Mar 5, 2025 · The article explains various methods to access and manipulate column names in a Pandas DataFrame, including using the . agg can take a dictionary but the keys must be individual columns. vexqg fzurs hjlzc sxace fjtxvu paw kpons psjy lvh bjlgfzl icc cxpp xbsiv npidt fmvb