Convert all nested dictionary keys to lowercase python. However, I am running into a lot of errors.

When applied to a string, it converts all the characters in the string to lowercase. Hot Network Questions Mar 5, 2023 · As a pre-task follow this simple three steps. lower or str. Method #1: Using Naive Approach Step-by-step approach : Define a function named insert that takes two parameters, a dictionary (dct) and a list (lst). To copy it over: def nested_set(dic, keys, value): for key in keys[:-1]: dic = dic. items()) return new_dict a = {'Foo': Hello, 'Bar': World} print I had a similar problem to solve: I wanted to replace keys in underscore lowercase convention for camel case convention and vice versa. Convert all dictionary keys to lowercase in python; Python - regex , remove all single characters,replace all single chars,char; Convert all string values in a list to integers using python; Loop through string characters in Python; String characters to list items using python; Get first N characters from a string in Python Apr 18, 2023 · Nested Dictionary Python to Pandas DataFrame. The flatten_dict() function has to be applied on each record in a list of dictionaries, meaning you can use either a Python loop or a list comprehension. Here’s an example: original_dict = {'Name': 'Alice', 'AGE': 'TWENTY-FIVE', 'Country': 'USA'} lowercase_dict = {**{k. Step-by-step approach: Apr 27, 2023 · The modified converted list is : [{'a': 1, 'b': 2}, {'c': 3, 'd': 4}] Time complexity: O (n*n), where n is the number of key-value pairs in the dictionary. Removing Nested Dictionary Elements. Then use list (obj) with this group as an object to convert it to a list. Let’s explore how to create and use this data type! Apr 4, 2023 · Given a nested dictionary, the task is to convert this dictionary into a flattened dictionary where the key is separated by ‘_’ in case of the nested key to be started. 7 or later for the sake of some purely Apr 10, 2023 · The function takes a nested dictionary, a list of keys, and a value as inputs. Any help would be hugely appreciated! For any nested dictionary, it finds it will flatten it in a way that the key renames to the full path. Though str. 0. loads(json. They are two Feb 21, 2024 · With Python 3. Tried the following code: if isinstance(v, dict): for i, j in v. upper()] = v. We are also using the lower() function of Python String to convert the key text to lowercase. However, I am running into a lot of errors. This functi Feb 13, 2024 · Here is a function that updates nested dictionaries by searching for a specified key no matter how deeply it is nested: def update_nested_dict(d, key, value): for k, v in d. e. Use regular expressions to replace ‘,’ with ‘-‘ or ‘^’ for list or tuple values respectively. you'll need to nest another dictionary comprehension inside. Apr 7, 2023 · Method #3: Using a for loop. return result. df = [ {'A': " {'value': '1'}", 'B': " {'value': '2'}"}] The keys are not able to be changed. def convert_case(str_camelcase): # This function takes in a string in camelCase and converts it to snake_case str_snake_case = "" for ele in I wish to convert all the objects to dictionaries. nested_dict = { 'dictA': {'key_1': 'value_1'}, 'dictB': {'key_2': 'value_2'}} Here, the nested_dict is a nested dictionary with the dictionary dictA and dictB. upper()] = d1. Syntax: Nov 18, 2021 · For my purpose I would like to convert the nested dictionary into a pandas dataframe of the form: Python Pandas: Convert nested dictionary to dataframe May 2, 2013 · 0. loads() I get the following output: So far so good, I can access the Data value via updatedRequest['Data']. # interface for dictionary-like objects. Create an outer defaultdict with dict as its default value. keys(): print i for j in d[i]. Nov 12, 2013 · Convert all keys in dictionary to lower case with dictionary comprehension. my_dict = {'Name': 'John', 'Age': 25, 'City': 'New York'} # Converting keys and values Oct 4, 2022 · The keys() method in Python Dictionary, returns a view object that displays a list of all the keys in the dictionary in order of insertion using Python. iteritems()} Result. Apr 26, 2023 · Given a flattened dictionary, the task is to convert that dictionary into a nested dictionary where keys are needed to be split at '_' considering where nested dictionary will be started. As a bonus, I've also supported lists and tuples during the recursion, in addition to the set on the provided example. ”. 3. items(): if k == key: d[k] = value elif isinstance(v, dict): update_nested_dict(v, key, value) This recursive function circulates through the dictionary and its sub Sep 14, 2015 · With this solution, you need to flatten the dictionary, because csv. upper()] = j. Python3. else: d[k. Converting a list of tuples to a dictionary. my_dict = {'KEY1': 'Hello', 'Key2': 'World'} new_dict = dict((k Mar 25, 2022 · In this tutorial, you’ll learn about Python nested dictionaries – dictionaries that are the values of another dictionary. keys(): print j OR. Method #2 : Using items () + list comprehension. Aug 18, 2023 · Convert a List to a Dictionary using a loop. dumps(d, ensure_ascii=False). Another way is to add the whole dictionary in one go, Nested_dict [dict] = { ‘key’: ‘value’}. from_dict () method constructs a DataFrame from a dictionary. Exercise 5: Create a dictionary by extracting the keys from a given dictionary. You’ll also learn how to work with nested dictionaries to convert them to a Pandas DataFrame. Return a set containing all nested keys. like @BHISM NARAYAN said: a dictionary is not subscriptable. casefold() as well. alphlower = {k. If you want to convert a nested dictionary to a Pandas DataFrame, you’ll have to flatten it first. Feb 12, 2024 · Given a flattened dictionary, the task is to convert that dictionary into a nested dictionary where keys are needed to be split at '_' considering where nested dictionary will be started. update(dict((k, v. Auxiliary space: O (n), to store the keys and values in dictionary. Exercise 3: Print the value of key ‘history’ from the below dict. basically if you replace [int(v)] with something like [dict((a,int(b) for (a,b) in v. Return the “converted_dict”. Nested Dictionaries in Data Analysis. If you want to create a nested dictionary given a list (arbitrary length) for a path and perform a function on an item that may exist at the end of the path, this handy little recursive function is quite helpful: def ensure_path(data, path, default=None, default_func=lambda x: x): """. Auxiliary space: O(N*M), as it creates a new dictionary with the same number of keys as the original dictionary, and each value in the new dictionary is a list with the same number of elements as the corresponding value in the original dictionary. So far, this is the best I can come up with, but it doesn't recurse Dec 13, 2019 · Use a dictionary comprehension and zip the list of dictionaries up with whatever list of keys you want. If the value is not a dictionary, it is left unchanged. Jul 11, 2010 · One more thing to take care is, ConfigParser converts the key values to lowercase hence in case you are converting the config entries to a dictionary cross check your requirements. Jan 31, 2018 · I'm working with a nested dictionary and I'm trying to figure out how to modify certain nested and non-nested keys/values effectively. 5+, the ** unpacking operator can be used within a dictionary comprehension to neatly convert keys and values to lowercase in a single line of code. array (data) with this list as data to convert it to an array. And the way it's implemented by Python's json module. . for eg. If a value is itself a dictionary, the function is called recursively to convert the keys in the nested dictionary as well. Other Ways to Convert a Python String to Lowercase. This can easily performed using just a one line with the help of list Jun 9, 2015 · Just use a comprehension to run through the dictionary again and convert all keys to lowercase. items()} def convert_list(lst): return [convert_value(item) for item in lst] def convert_value(v): if isinstance(v, dict): return convert_dict(v) elif isinstance(v, list): return convert_list(v) # more elifs. Apart from the inbuilt method “. Set the orient keyword argument to index. It's a collection of dictionaries into one single dictionary. , don't care about what value corresponds to it), then make a set instead -- i. For me I was having camel-case keys hence, had to change some amount of code when I started using the dictionary instead of files. Here’s an example: def flatten_dict(d: dict) -> dict: Feb 10, 2020 · Here's the working code. Oct 24, 2017 · As you can see flattenReturn generates a new dict filtering the values which are dictionaries and then updates it with their key-values to flatten it while the second option modifies the dict in place. a: dict(zip(k, v)) for a, k, v in zip(. Python set dictionary nested key with dot delineated string. # Sample dictionary. lower() for k in thedict} if you're happy with your code working only in Python 2. lower()) for k,v in item. For example, if the original string is “Hello World,” applying `lower ()` would result in “hello world. theset = set(k. I'm new to python and have tried several approaches but failed in achieving so, please help. __delitem__(self, key): Removes the key(s) and its associated value(s) from the nested dictionary. May 3, 2017 · keys() method returns a view object that displays a list of all the keys in the dictionary. In a nested dictionary, the values mapped to keys are also dictionaries. Jun 7, 2012 · I came up with one scenario where in I wanted to use json. Exercise 2: Merge two Python dictionaries into one. Nov 3, 2022 · Then with the . append(tuple(keys + list(d))) else: result. keys(example). ascii_lowercase[0:len(input)]], input))} Jan 2, 2021 · Convert all keys in dictionary to lower case with dictionary comprehension. sections (): the_dict [section] = {} for key, val in Jan 10, 2019 · After conversion using json. keys()[0] will give TypeError: 'dict_keys' object is not subscriptable. search() To check if the sequence of one upper case Mar 14, 2022 · pop(self, key, default=None): Removes and returns the value associated with the given key(s) from the nested dictionary, or returns the default value if the key(s) is not found. This should do what you want: d['A']['b'] = 3. There are several ways to remove elements from a nested dictionary. Jul 28, 2014 · What I need is a multiindex where each level corresponds to the keys in the nested dict and the rows corresponding to each element in the list as shown above. The keys in any level can be either int or string. g. Otherwise, you’ll get weird indexing and possibly a dictionary for the value of a single cell. lower()) … will work as long as: Your values are all of type dict, list, str, float, int, bool, and NoneType. In this article, we will look at two different ways. from collections. Otherwise, it simply updates the value in the source dictionary. lower ()` method to make a Python dictionary case insensitive: python. This will convert all the values to lower, But according to the condition we should focus on only key1 which need to be lower. May 6, 2023 · Table of contents. May 10, 2023 · This method uses a dictionary comprehension to create a new dictionary where all keys are converted to upper case. 1. normalize in pandas but values were of str type. Converting two lists of the same length to a dictionary. Because there is an unknown number of 'Value' keys, I'm uncertain as to what Oct 19, 2020 · You can use dict. A list would be more suitable. e. lower(), v. lower(): v for k, v in alphabet. lower ()` method on each key in the dictionary. defaultdict to make your life easier. By the end of this tutorial May 23, 2023 · Solution 1: In Python, we can convert the keys and values of a dictionary to lowercase using various methods. You can use ast. keys()[0] and dict. loads method. I faced a problem because of this. keys() ]) >>> newDict {'mykey': {'mykey2': [u'abc']}} May 6, 2024 · Using a nested dictionary in Python is a way to create a hierarchical data structure for your application. items(): # the key will be a flattened tuple. You’ll learn how to create nested dictionaries, access their elements, modify them and more. Python Set all dictionary values to lower case with specific key. >>> d = {'data1': {'yes': 'abc'}, 'data2': {'yes': 'xyz'}} >>> d['data1']['no'] = d Jul 21, 2010 · If all you care is where a key is in the dict or not (i. lower() for k in thedict) (in every version of Python, or {k. But I'll summarize here: lowered = json. Here is an example using a subset of ascii lowercase letters: { pair[0]: pair[1] for pair in list(zip([*string. For simple situations, you can use the following example to convert all keys to lower case: Object. To create a new dictionary with the flattened keys it maintains in memory a Python list. Initialize a tuple named ‘test_tuple’ with nested tuples as its elements. Below are some common methods to create a Python Nested Dictionary. However, it has a problem. def nested_keys(d) -> set: """. There are two ways of accessing May 8, 2023 · 2. One way to add a dictionary in the Nested dictionary is to add values one be one, Nested_dict [dict] [key] = ‘value’. Using {} Literal Syntax. The resulting dictionary has sections as keys which point to a dict of the sections options as key => value pairs. append(tuple(keys + [d])) return result. Dict = { } Feb 21, 2017 · The dict_lowercase_content() makes no assumptions about what keys are present in the dictionary; it'll create a shallow copy of all the keys, and if a content key is present it is lowercased. from_dict() method. Finally, the dictionary is returned as the result. Jun 10, 2023 · The addition of elements to a nested Dictionary can be done in multiple ways. Convert the value to a string using the str () function. If it is, then it iterates over each key-value pair in the Jun 14, 2014 · A convenience function to do this might look something like: def as_dict (config): """ Converts a ConfigParser object into a dictionary. First of all call dict. If you want to get all nested keys of a dictionary, you will need to define your own function. """. For example, tree_dict = 42 leads to a nested dict What is Nested Dictionary in Python? In Python, a nested dictionary is a dictionary inside a dictionary. lower()”, there are different ways of converting uppercase letters to lowercase letters in Python. The first version works, and it's somewhat fast. Parameters: There are no parameters. Examples: Input: dictionary = {'Hello': 600, 'world': 300, 'BTechGeeks': 900 Oct 25, 2019 · If you're fine with losing the key to which your inner dict belongs to (you did not specify what to do with it), I would do it recursively: def unnest_dict(d): result = {} for k,v in d. casefold() will pass. The prices of orange, grapes, and tomatoes are printed by chaining get() calls with the respective keys for fruits and vegetables, providing a safe way to handle potential missing keys. Returns: A view object is returned that displays all the keys. int(v) -- v is a dictionary! this line here, you are trying to convert a dictionary to an integer. setdefault(key, {}) dic[keys[-1]] = value. 6. 123: {'name' : 'Alice', 'age': '23'}, Apr 9, 2023 · Time complexity: O(N*M), where N is the number of keys in the dictionary and M is the length of the longest list in the dictionary. The following is an example of how to use the `str. At last, call numpy. Of course, if you can be certain that only the content key is important and always present, you could just create entirely new dictionaries with just that Jan 4, 2024 · Creating a nested dictionary in Python can be done in multiple ways. You can update the list using the below code: item. When the orient argument is set to index, the keys of the dict will be rows. Exercise 1: Convert two lists into a dictionary. Explanation: When you write d['A'] you are getting another dictionary (the one whose key is A), and you can then use another set of brackets to add or access entries in the second dictionary. Initialize a list named ‘keys’ containing the desired keys for the output dictionary. Feb 17, 2014 · You can use tuple unpacking combined with collections. Method #1: Using Naive Approach. This method works by initializing an empty dictionary and then iterating through the list in step 2. lower() method, it converts those letters to lowercase. items())] didn't test that out but you get the idea, also nesting that might get a little messy I have this Python dictionary that needs to be converted to lowercase. This is my favorite, to only convert the keys, which is what I was looking for. answered Jan 9, 2020 at 20:51. Here are some examples: Method 1: Using a for loop to iterate over the dictionary and convert the keys and values to lowercase. 4. If you know the key of the item you want to remove, the pop() method is a Apr 28, 2017 · >>> myDict = {'myKey': {'myKey2': [u'Abc']}} >>> newDict = dict([ (k1. ) with custom ones, and would not work with keys that are not valid attribute names. lower(): v for k, v in original_dict. Sep 11, 2023 · Python Nested Dictionaries in Real-World Applications. This is useful when you have non-ascii characters and matching with ascii versions(eg: maße vs masse). Method #1 : Using loop + enumerate () This is brute way in which this task can be performed. Thanks for pointing it out, i have updated my answer. items () to return a group of the key-value pairs in the dictionary. """ the_dict = {} for section in config. Python How to Access Nested Dictionary (with 5+ Examples) By Artturi Jalli. Aug 8, 2018 · 1. Converting two lists of different length to a dictionary. Convert all keys of the dictionary into lower case - Here I will convert all the keys of the dictionary into lower case using the lower() function. Initialize an empty list named ‘res’ to store the resulting dictionaries. This results in a complete merging of the dictionaries at all levels. Nested dictionaries in Python are not just a theoretical concept — they have practical applications in various fields such as data analysis and web development. Converting a list of alternative key, value items to a dictionary. Though the nested JSON won't get converted to the dictionary that's why I've added the recursive function to address the nested dictionary present in the JSON. values()[0] but a dictionary is the wrong data structure for this type of thing. The set method in ( Setting a value in a nested python dictionary given a list of indices and value ) seems more robust to missing parental keys. Dictionaries, like lists, can hold a variety of data types, including integers, floats, strings, NaN, Booleans, lists, arrays, and even nested dictionaries. Aug 23, 2020 · Convert a dictionary into a special dictionary python. – ggll Jan 5, 2024 · The `lower ()` method is a string method in Python. Add the key-value pair to the “converted_dict”. In short, I'm trying to do the following: take a nested value and switch it with a non-nested key; rename a nested key. Here ( Data Science Learner ) is some code tweaks with output and sample python code. Args: d (dict): dictionary (nested or not) to be converted. In each iteration, the key-value pair is added to the dictionary using the current element as the key and the next element as the value. I can convert an object to a dictionary by using the __dict__ property, no problem. Remove an Item by Key. In case you are looking for how to convert all keys of a dictionary into lower case: Python. items(): if isinstance(v, dict): result. This is useful for standardizing and comparing strings without considering case differences. The main block I'm struggling with is here: Jun 17, 2020 · How to convert Python dictionary keys values to lowercase - You can convert Python dictionary keys/values to lowercase by simply iterating over them and creating a new dict from the keys and values. lower(), dict([ (k2. This functi Aug 23, 2019 · elif isinstance(d, list): result. Nested Feb 7, 2019 · I am writing a python application where I have a variable dictionary that can be nested upto any level. If found, print 'Yes', otherwise 'No'. Exercise 4: Initialize dictionary with default values. items() if k=='key1')) Output. Mar 28, 2021 · robots is a list of dictionaries, so try the following. Aug 30, 2014 · The nested list is quite large, so I've only included as sample here :) My current attempts have yielded the best option as: newDict = dict. If your purpose is to matching with another string by converting in one pass, you can use str. Examples: Input : GeeksOutput : YesInput : geeksforgeeksOutput : NoPython regex to find sequences of one upper case letter followed by lower case lettersUsing re. lower() for x in myDict[k1][k2]]) for k2 in myDict[k1]. using ast. g updatedRequest['Data']['Value0']['ReferenceValue'] ). append(tuple(keys + d)) elif isinstance(d, set) or isinstance(d, tuple): result. Mar 12, 2024 · Access Value Inside Python Nested Dictionaries Using get () Method. For example,def lower_dict(d): new_dict = dict((k. first converting to list and then indexing with numbers is ok. The DataFrame. If you do not want to use dict comprehension then you can use the below code to convert dictionary keys to lowercase format. How nested the dictionary will be is variable which makes it a bit complicated. If the list of keys has only one key, the function adds the value to the nested dictionary at that key. Jan 26, 2021 · the problem is that you do one the comprehension inside the tuple and over the values, do it over the items instead, and the second level over the items of those Jun 7, 2020 · Pandas: Convert dictionary to dataframe where keys and values are the columns 1 Convert Pandas DataFrame to dictionary where columns are keys and (column-wise) rows are values The older answers have some pretty good tips in them, but they all require replacing standard Python data structures (dicts, etc. Oct 28, 2020 · 4. Here's a basic example of a dictionary that I'm working with: Feb 1, 2019 · I have a nested dictionary that looks like this: data = {'Name': {}, 'Contact': {} } It might seem clear that what I'm trying to do is take the names and phone numbers from the JSON and sort them into the nested dictionary under the correct keys. That looks like this: output = {. To access a nested dictionary in Python, apply the access operator twice (or more). Function: Jan 9, 2020 · In python, append is only for lists, not dictionaries. The most straightforward way to create a nested dictionary is to use the {} literal syntax, where you manually specify both the keys and the values in the dictionary. Small typo: you need an additional () around the dict() argument that is returned. which produces the output with unnecessary keys and height and weight rationalization as follows: Jul 27, 2021 · How to Flatten a Dict in Python Using your Own Recursive Function + Generators. lower() Save key and value in a new dictionary, append it to the new list; This should do it: Nov 3, 2016 · This easiest way is to build the dictionary starting from the inside out: tree_dict = {key: tree_dict} With an arbitrary terminal value: result = {k: result} Probably worth pointing out that if the leave has to be some other value than a dict, one can just initialise tree_dict accordingly. so it will work for resp = 'GBR' or 'gbr'. For example, let’s access the name of a student data dictionary with the student ID of 123: students = {. Jun 7, 2021 · Converting the nested dictionary to dataframe with, dictionary keys as column names and values corresponding to those keys as column values of the dataframe. Jun 13, 2018 · And then there's the way JSON is actually used in practice. forEach(key => { const value = example[key]; delete example[key]; example[key. Apr 20, 2023 · Write a Python Program to find sequences of one upper case letter followed by lower case letters. fromkeys(stations,{}) Which gives me: {1: {}, 2:{}, 4:{}} To which I'm at a loss how to combine both the keys and values to make my ideal dictionary. Convert values of a dictionary to lowercase How to lowercase all keys in json dict Mar 21, 2023 · Explanation : List converted to dictionary with index keys, just one row. Converting nested dictionary to dataframe with the keys as rownames and the dictionaries in the values To do this, we simply need to call the `str. My issue when attempting to convert this into a Python usable dictionary (e. However, I'm having trouble figuring out the best way to convert all the nested objects as well, without having to do each level explicitly. for i in d: print i for j in d[i]: print j output: . In this, we iterate through the index and value together using enumerate and create custom required dictionary. def flatten_dict(deep_dict): def do_flatten(deep_dict, current_key): for key, value in deep_dict. The dictionary consists of data that needs to correspond to case insensitive input, e. May 18, 2014 · To change a single dictionary just reference the dictionary you want to change. You can build a nested dictionary with as many levels of nesting as you need. literal_eval) this will convert str to dict. keys() ])) for k1 in myDict. update(unnest_dict(v)) else: result[k] = v. d = {“Name”: “John Smith”, “Age”: 25, “Occupation”: “Software Engineer”} Convert the keys to lowercase. items(): d1[i. This is inefficient, as we have to keep an entire data structure in memory just to serve as a To convert a nested dictionary to a Pandas DataFrame: Use the DataFrame. abc import Mapping. Loop through each key-value pair in the original dictionary. In data analysis, nested dictionaries can be used to store and manipulate complex data Jan 22, 2020 · Would like to convert only dictionary keys to UPPERCASE. def change_dict_naming_convention(d, convert_function): """ Convert a nested dictionary from one convention to another. Step-by-step approach : The function checks if the input dd is a dictionary. upper fails in such cases, str. But I want to convert all keys and values at all levels into strings. literal_eval, i type casted. Hope I'm making sense here. Jan 19, 2024 · Given a flattened dictionary, the task is to convert that dictionary into a nested dictionary where keys are needed to be split at '_' considering where nested dictionary will be started. How to create a nested dictionary from a Feb 10, 2022 · Your nested key seems like a JSON string that can be loaded into a dictionary using json. Then, you can simply loop through your list of tuples once, setting the values appropriately as you go. toLowerCase()] = value; }); You can convert all of the keys to upper case using toUpperCase() instead of toLowerCase(): Jul 16, 2015 · I just wanted to note (as this is one of the top results for converting from a nested dictionary to a pandas dataframe) that there are other ways of nesting dictionaries that can be also be converted to a dataframe (e. In this example, values in the nested market dictionary are accessed using the get() method. If you're comfortable with list and dictionary comprehension, you can zip up x with a lists of your key lists and values lists. literal_eval like below - df [column_name] = df [column_name]. dict. lower(), [x. 10-Aug-2022 May 18, 2017 · Basically the same way you would flatten a nested list, you just have to do the extra work for iterating the dict by key/value, creating new keys for your new dictionary and creating the dictionary at final step. Iterate over dictionaries in the list robots; Iterate over keys in each dictionary; Get value of each key in dictionary, convert them to lowercase using . Start a for loop to iterate over each nested tuple in ‘test_tuple’. 5. Otherwise, it creates a nested dictionary at the first key if it doesn’t already exist, and then recursively calls the function with the remaining keys and value. I think I can work a very crude solution but I'm hoping there might be something a bit simpler. x, In the above code snippet, we are using dict comprehension to convert all the keys of a dictionary(car) to lowercase letters. d[k. Jan 25, 2017 · If you don't know the number of levels, then a recursive solution is probably best: def convert_dict(d): return {str(k): convert_value(v) for k,v in d. nesting via columns). the following nested dictionary Jul 3, 2019 · One approach is to recurse on your dictionary until you find a non-dictionary value and pass down the current key as a tuple during the recursion. items()}} print(lowercase_dict) Jan 13, 2023 · 10 different ways to Convert a Python List to a Dictionary. Iterate nested dictionary: d = {'dict1': {'foo': 1, 'bar': 2}, 'dict2': {'baz': 3, 'quux': 4}} for i in d. Jun 10, 2022 · Mapping values and keys from a nested dictionary to columns. Let’s demonstrate a bad practice first, so you can get the idea of why flatten the data. Given a dictionary ,the task is to convert keys of dictionary to a list. apply (ast. lower()) for k, v in d. keys only returns the top level keys of the dictionary. DictWriter writes each row with a dict of the following pattern: {column1: data, column2: data, column3: data, } And you have to give the fieldnames, because a dict is unordered. fe rl eh ax ii wp nw lz js dz