Pandas series astype type () checks the datatype before and after conversion. Nominal Categories Nominal categories are Convert pandas. astype () method and how to use this method to change the datatype of pandas object (DataFrame/series) using specified operation (s). dtype or Python type to cast one or pandas. {col: dtype, …}, where col is a Regaining original data # To get back to the original Series or NumPy array, use Series. You can access the dtypes attribute on the DataFrame to verify that the column has been converted to category. If that doesn’t work, will try call to apply again with by_row="compat Feb 20, 2024 · Using errors='coerce' tells Pandas to set values to NaN (Not a Number) if they cannot be converted, a useful technique for cleaning data. : '2013-10-28' At the moment the dtype of the column is object. dtype or Python type to cast entire pandas object to the same type. Categorical docs: This method creates a pandas Categorical object (limited, and usually fixed, number of possible values (categories)), which represents a categorical variable. If that doesn’t work, will try call to apply again with by_row="compat Sep 21, 2016 · starting from the uncasted column-series, convert them into list (), iterate on them apply the function to the np. I’ll explain what the technique does, explain the syntax, and show you step-by-step examples. In this article, I will explain the astype() function, its syntax, parameters, and usage of how to convert single or multiple string columns into integer types with some examples. Factors in R are stored as vectors of integer values and can be labelled. astype(original_dtype) or np. Apr 2, 2019 · The method . This pandas. astype ¶ Series. where As OP didn't specify the dataframe, in this answer I will be using the following dataframe How can I preserve nulls after converting to string? I'm working with social security numbers, where it's necessary to go back and forth between float and string. dtype or Python type to cast one or more of the DataFrame’s columns to column-specific types. dtype or Python type as a parameter to the Note that using copy=False and changing data on a new pandas object may propagate changes: Parameters dtypedata type, or dict of column name -> data typeUse a numpy. factor()?) Also, what's the difference between 将数据转换为合适的格式能够让数据高效计算，同时也能匹配指定类型的操作方法。astype () 方法将 pandas 对象强制转换为指定的 dtype 类型对象，它支持 DataFrame、Series 和 Index 等对象。 Dec 27, 2024 · `pandas. This method allows the conversion of the data types of pandas objects, including DataFrames and Series, to the specified dtype. astype Change the data type of a Series, including to boolean. Examples Feb 5, 2020 · Development Code with agent mode Fix issue #31708 Series. Among its essential methods, the astype method is a powerful tool for converting the data types of columns or elements in a DataFrame or Series, enabling precise control over data representation. Use the downcast parameter to obtain other dtypes. Apr 26, 2021 · This article explains the Python pandas Series. It supports casting entire objects to a single data type or applying different data types to individual columns using a mapping Sep 3, 2023 · pandas. However even after removing both of these signs, . cat. array () single elements, and append the results into a temporary list. Method 1: Using astype(int) One of the most straightforward methods to convert a pandas Series to integers is using the astype(int) method. to_numeric(arg, errors='coerce') first especially when the DataFrame column or series has the possibility of holding numbers that cannot be converted to Numeric, as it converts those numbers to NaN, I then drop the NaN if desired, then use DataFrame. Using this astype () method in pandas. Series Cast data type of all columns of pandas. Parameters: dtypestr, data type, Series or Mapping of column name -> data type Use a str, numpy. Please note that precision loss may occur if really large numbers are passed in. Prior to pandas 1. g Dec 4, 2023 · The astype () method in Pandas is used to cast a pandas object, such as a DataFrame or Series, to a specified data type. astype ('string'): pandas. numpy. There is a column with amounts in dollars, which uses commas as decimal points. astype(int64) but got an error: NameError: name 'int64' is not defined The column has number of people but was Regaining original data # To get back to the original Series or NumPy array, use Series. astype(dtype: str | type | pd. dtype or Python type to cast one or more of the DataFrame Jan 29, 2017 · Here df is a pandas series and its contents are 2 strings, then I can apply astype(float) on this pandas series, and it correctly convert all string into float. dtype) is self return self. Parameters ---------- dtype : str, data type, Series or Mapping of column name -> data type Use a str, numpy. csv file to a Pandas dataframe as below. astype Change the data type of a DataFrame, including to boolean. copybool, default TrueReturn a copy when copy=True (be very careful Series. Parameters: dataSeries or CategoricalIndex Examples >>> s = pd. copybool To cast a DataFrame to specific datatype, call astype () method on this DataFrame and pass the datatype as parameter to this function. astype () function is used to convert a particular column data type to another data type. Jun 26, 2025 · DataFrame. Jul 28, 2023 · When working with time-series data in Pandas, you can use either pandas. Series. {col: dtype, …}, where col is a column Apr 26, 2020 · 1 https://pandas. Due to the internal limitations of Jun 26, 2025 · By using pandas to_datetime() & astype() functions you can convert column to DateTime format (from String and Object to DateTime). I have tried to convert the dtype using the . In pandas, how can I convert a column of a DataFrame into dtype object? Or better yet, into a factor? (For those who speak R, in Python, how do I as. asarray(categorical): Oct 28, 2013 · I have a Pandas data frame and one of the columns, have dates in string format of YYYY-MM-DD. There are three methods to convert Float to String: Method 1: Using DataFrame. Mar 7, 2014 · A new answer to reflect the most current practices: as of now (v1. 4), neither astype('str') nor astype(str) work. 24, it is possible to assign missing values to integer variables without promoting them to floats. Strings in the Series/Index with length greater or equal to width are unchanged. by_rowFalse or “compat”, default “compat” If "compat" and func is a callable, func will be passed each element of the Series, like Series. dtype or Python type to cast one or 2. This was unfortunate for many reasons: You can accidentally store a mixture of strings and non-strings in an object dtype array. astype () not working? I need to change the datatype of an imported DataFrame which has everything as 'object'. If your DataFrame holds the DateTime in a string column in a specific format, you can convert it by using to_datetime() function as it accepts the format param to specify the format date & time. to_numeric(). It’s better See also Series. DataFrame individually Specify data type (dtype) when reading CSV files with read_csv() Specify the Dec 9, 2024 · What is the Pandas astype () Method? The astype () method in Pandas converts the data type of one or more columns in a DataFrame or a Series to a specified type. astype () method. The result index will be the sorted union of the two indexes. astype # Series. The axis labels are collectively called index. In Pandas, we can convert a regular Pandas Series to a Categorical Series using either the astype() function or the dtype parameter within the pd. Basic usage Just pick a type: you can use a NumPy dtype (e. dtype or Python type to cast one Apr 21, 2020 · This answer contains a very elegant way of setting all the types of your pandas columns in one line: # convert column "a" to int64 dtype and "b" to complex type df = df. datetime64). Series containing integers, but I need to convert these to strings for some downstream tools. astype (). import pandas as pd import numpy Apr 12, 2024 · The astype() method casts a pandas object to the supplied data type. Method 1: Using DataFrame. dtype or Python type as a parameter to the pandas. {col: dtype, …}, where col is a column label and dtype is a numpy. At its core, the syntax is refreshingly simple: Jan 22, 2014 · I read data from a . At first glance, `astype (str)` seems preferable: it’s vectorized, concise, and aligns with pandas’ "vectorized operations are faster" mantra. Example 5: Casting to Categorical Data Types for Efficiency df = pd. Mar 21, 2022 · In this tutorial, I’ll explain how to use the Pandas astype function to modify the datatype of Pandas dataframe columns and Pandas objects. astype() and pandas. And the astype () method will return a series object with the converted data type. astype() The astype() method enables you to be explicit about the dtype you want your DataFrame or Series to have. Here it will be used to convert How can I preserve nulls after converting to string? I'm working with social security numbers, where it's necessary to go back and forth between float and string. cat # Series. Convert a numeric column from object to integer: astype() parses each value in the column to the target type. Alternatively, use {col: dtype, …}, where col is a column label and dtype is a numpy. {col: dtype, …}, where col is a column Aug 27, 2022 · if is_dtype_equal(self. 2. Seriesは一つのデータ型dtype、pandas. since many pandas methods have an inplace kwarg. map Using pandas. 1. astype`方法是Pandas库中用于将Series对象的数据类型转换为指定类型的方法。 以下是该方法的详细介绍，包括语法、参数、示例及结果。 pandas. dtype or Python type to cast one pandas. It's very versatile in that you can try and go from one type to any other. Sep 15, 2022 · Pandas Series - astype () function: The astype () function is used to cast a pandas object to a specified dtype dtype. Series(['red', 'blue', 'green', 'red', 'blue']) df = df. astype(self. apply Using numpy. For e. Mar 26, 2019 · However: this seems clunky, having to reassign the series, esp. This is especially useful when you need to ensure that columns have the correct type, such as converting strings to integers or floats to strings. pydata. DataFrame. I tried to convert a column from data type float64 to int64 using: df['column name']. DataFrame. Here's an example with a DataFrame: I tried to convert a column from data type float64 to int64 using: df['column name']. replace Using pandas. Parameters String and category types ¶ The pandas. Jun 3, 2025 · To convert a string column to an integer in a Pandas DataFrame, you can use the astype() method. Here, we created a sample data frame with two columns containing integers and strings and then we converted the string column to a float column using the astype () function. Jan 15, 2024 · pandas. astype () still doesn't seem to work even though I assigned the result. As per the documentation, a Series can be converted to the string datatype in the following ways: Jun 18, 2024 · In this article, I will explain the astype() function and using its syntax, parameters, and usage how we can convert Pandas Series data type from one type to another type with multiple examples Dec 9, 2024 · What is the Pandas astype () Method? The astype () method in Pandas converts the data type of one or more columns in a DataFrame or a Series to a specified type. Hence, it provides a flexible way to convert the data types of one or more columns in a DataFrame. 0 there is now a dedicated string datatype: 1) You can convert your column to this pandas string datatype using . bool_ NumPy boolean data type, used by pandas for boolean values. astype. astype(dtype, copy=True, errors='raise', **kwargs) [source] ¶ Cast a pandas object to a specified dtype dtype. Using this, however, doesn't seem to work (starting out with the same dataframe at the top): pandas. {col: dtype, …}, where col is a column Feb 19, 2024 · For example, if you have a Series ['1', '2', '3'], the goal is to convert it to a Series with integer values: [1, 2, 3]. where As OP didn't specify the dataframe, in this answer I will be using the following dataframe pandas. astype(int) or pandas. to_numeric() methods you can convert a column from string/int type to float. Aug 30, 2018 · test = ['False','False','True'] test = pd. ExtensionDtype or Python type to Jul 27, 2022 · For the sake of simplicity, can I just use astype ('string') instead of astype (pd. html Looks like a type of uppercase in asType I looked for the uppercase and could not find it. dtype, dtype): # Ensure that self. 0 release pandas-dev/pandas Jul 23, 2025 · Method 1: Using DataFrame. StringDtype ()) mapped to StringDtype internally? Mar 20, 2018 · I have a pandas. {col: dtype, …}, where col is a column pandas. If conversion fails (e. Aug 9, 2023 · Contents List of basic data types (dtype) in pandas object type and string The special data type: object Note: String methods Note: NaN Cast data type (dtype) with astype() Cast data type of pandas. astype method can also convert numeric series into strings if you pass str. Series [source] Cast a pandas object to a specified dtype dtype. Jul 15, 2025 · Series is a one-dimensional labeled array capable of holding data of the type integer, string, float, python objects, etc. cat() [source] # Accessor object for categorical properties of the Series values. Explore techniques like astype, dt. Jun 19, 2025 · Among its many powerful features, the ability to convert data types efficiently is crucial for data preparation and analysis. 5k次，点赞6次，收藏7次。在Pandas中，astype方法用于将DataFrame或Series的数据类型（dtype）转换为指定的数据类型。它是数据类型转换的常用方法，支持将列转换为多种类型，比如整数、浮点数、字符串、布尔值、类被类型等_pandas astype 85 you can set the types explicitly with pandas DataFrame. astype () DataFrame. dtype, pandas. 3 documentation For standard rounding (rounding half up) and for rounding down and up decimals (floor and ceiling), use functions from NumPy or the decimal module in Python's standard library. StringDtype extension type. astype() to convert the datatype to the exact numeric data type I desire Jul 7, 2025 · DataFrame. bool), or pandas-specific types (like the categorical Jun 19, 2025 · The astype() method is a fundamental tool in the pandas toolkit, allowing for seamless conversion of data types within a Series object. May 6, 2017 · Mapping Categorical Data in pandas In python, unlike R, there is no option to represent categorical data as factors. astype(dtype, copy=True, errors='raise') [source] # Cast a pandas object to a specified dtype dtype. Here it will be used to convert Nov 1, 2022 · 7 There are various ways to achieve that, below one will see various options: Using pandas. astype(dtype, copy=<no_default>, errors='raise') [source] # Cast a pandas object to a specified dtype dtype. modin. astype('bool') But it gives the same result, what is going on here and how do I properly convert the datatype? I've tried using map and replace to change the values before conversion but neither changed the outcome. astype(dtype, copy=True, errors='raise')[source] ¶ Cast a pandas object to a specified dtype dtype. Today’s article aims to explain how to use pandas astype effectively, a helpful resource for our customers while optimizing data handling on their bare metal hosting. Jun 12, 2025 · Explanation: astype (str) changes the entire column dt from datetime to string type. astype Aug 23, 2016 · 35 With pandas >= 1. astype You can do something like this : python Copy 6 days ago · @final def astype ( self, dtype, copy: bool_t | None = None, errors: IgnoreRaise = "raise" ) -> Self: """ Cast a pandas object to a specified dtype ``dtype``. pandas. It's highly flexible and supports converting data to numeric, string, or even custom types like categories. 24+ and an integer column it works fine: Feb 15, 2025 · This is where pandas astype() steps in like a data wizard. Jan 4, 2018 · 54 1. astype('category') print (df) # Output: # 0 red # 1 blue # 2 green # 3 red # 4 blue dtype: category Converting to a categorical type The astype() function in pandas is used to cast a pandas object to a specified dtype. It supports casting entire objects to a single data type or applying different data types to individual columns using a mapping pandas. In this tutorial, we will learn the syntax of DataFrame. to_numeric() functions. This comprehensive guide delves into the astype() method of pandas Series, exploring its capabilities, use cases, and best practices to help you master this essential technique. Parameters dtypedata type, or dict of column name -> data type Use a numpy. How do I convert the column va Mar 9, 2022 · In the pandas series, the astype () method is used to convert the data type of the pandas series object. zfill(width) [source] # Pad strings in the Series/Index by prepending ‘0’ characters. These are separate namespaces within Series that only apply to specific data types. ExtensionDtype or Python type to cast entire pandas object to the same type. What is astype()? Simply put, astype() helps you convert the data type of a column (or an entire DataFrame) in pandas. astype(self, dtype, copy=True, errors='raise', **kwargs) [source] ¶ Cast a pandas object to a specified dtype dtype. If you use pandas 0. Series we can convert the datatype of the series object to the specified data type, to achieve this, we need to send a numpy. to_datetime() function. np. astype Using pandas. {col: dtype, …}, where col is a column Feb 15, 2025 · This is where pandas astype() steps in like a data wizard. We can change them from Integers to Float type, Integer to String, String to Integer, Float to String, etc. int16), some Python types (e. , non Parameters: dtypestr, data type, Series or Mapping of column name -> data typeUse a str, numpy. Parameters dtypedata type, or dict of column name -> data typeUse a numpy. Bonus One-Liner Method 5: Using List Comprehension and float() List comprehension with Python’s built-in float() function allows for a quick one-liner solution to convert a Series to float. May 23, 2017 · Expanding on @Ryan G mentioned usage of the pandas. If func is a list or dict of callables, will first try to translate each func into pandas methods. astype You can use pandas. Series | dict[str, type], copy: bool = True, errors: Literal['raise', 'ignore'] = 'raise') → pd. copybool Jul 15, 2025 · In this post, we'll see different ways to Convert Floats to Strings in Pandas Dataframe? Pandas Dataframe provides the freedom to change the data type of column values. 6 days ago · Pandas offers multiple ways to achieve this, but two methods stand out: `astype (str)` and `apply (str)`. Jun 5, 2024 · The pandas astype function provides a straightforward method for changing the data type of columns in a Pandas DataFrame. astype() can be very useful when you need to convert the data types of one or more columns in a DataFrame or a Series. astype("category") >>> s 0 a 1 b 2 b 3 c 4 c 5 c dtype: category Categories (3, object): ['a', 'b', 'c'] argstuple Positional arguments passed to func after the series value. Apr 18, 2020 · I am attempting to work on a data set from the Museum of modern art and wish to convert some of the series to integer values (for calculations later on). Mar 11, 2025 · Learn how to convert a pandas series of datetime to string in Python with easy-to-follow methods. asarray(categorical): Feb 19, 2024 · The code snippet above demonstrates the conversion of a pandas Series filled with date strings to a Series of pandas Timestamp objects by utilizing the pd. astype (str, skipna=True) vanished in the 1. Use a str, numpy. Series() constructor. If we have our data in Series or Data Frames, we can convert these categories to numbers using pandas Series’ astype method and specify ‘categorical’. , float, np. 0, object dtype was the only option. astype({ pandas. Sep 20, 2019 · I think the problem is with your pandas version. For one of the columns, namely id, I want to specify the column type as int. astype(dtype, copy=True, raise_on_error=True, **kwargs) and pass in a dictionary with the dtypes you want to dtype here's an example: The astype() method converts a Pandas Series or DataFrame column to a specified data type. org/pandas-docs/stable/reference/api/pandas. dtype or Python type to cast one or more of the DataFrame pandas. Series from dtype object to float, and errors to nans [duplicate] Asked 11 years, 2 months ago Modified 3 years ago Viewed 265k times I have a pandas data frame where the first 3 columns are strings: ID text1 text 2 0 2345656 blah blah 1 3456 blah blah 2 541304 blah Accessors # pandas provides dtype-specific methods under various accessors. astype() function is used to cast a column data type (dtype) in pandas object, it supports String, flat, date, int, datetime any many other Jul 12, 2024 · I'm not an expert pandas user, but looking at the documentation on Categorical data it seems like pd. Let’s see the program to change the data type of column or a Series in Pandas Dataframe. Note the dtype in the following example: Jun 3, 2025 · To convert a string column to an integer in a Pandas DataFrame, you can use the astype() method. The astype method can be used to convert the data type of columns in a Pandas DataFrame or elements in a Pandas Series. DataFrame(test) test = test. Obviously, caution should be applied when ignoring errors, but for this task it comes very handy. DataFrameは列ごとにそれぞれデータ型dtypeを保持している。 dtypeは、コンストラクタで新たにオブジェクトを生成する際やCSVファイルなどから読み込む際に指定できる。 Mar 19, 2025 · Converting Pandas DataFrames and Series Pandas is another widely used library for data analysis in Python. to_numeric # pandas. strftime, and list comprehension to manipulate datetime formats effectively for your data analysis needs. Examples on Pandas astype () Function in Python Example 1: Converting data type of a Series pandas. {col: dtype, …}, where col is a pandas. Using pandas. In this article, I will explain how to convert one or multiple string columns to float type using examples. We would like to show you a description here but the site won’t allow us. It returns a pandas Categorical series that contains the original data along with the categories. So suppose I had a Series object: import numpy as np import pandas as pd x = pd. astype(dtype, copy=True, errors='raise') [source] ¶ Cast a pandas object to a specified dtype dtype. Parameters: dtypestr, data type, Series or Mapping of column name -> data typeUse a str, numpy. Serie pandas . StringDtype ()) and get exactly the same behavior, including conversion of series with only ints/floats or of nullable versions of such numeric data types? Are both astype ('string') and astype (pd. This approach is simple and direct, converting the entire Series to the specified type. If you need something specific, you can click on any of the following links. , 'int32', 'category') or Python/Numpy types (e. str. astype(dtype, copy=None, errors='raise') [source] # Cast a pandas object to a specified dtype dtype. Method 2: Using Series astype() Method The Series astype() method is used to cast a pandas object to a specified dtype. astype () function in pandas cast a pandas object such as a DataFrame or Series to a specified data type. Using strftime () The strftime () method formats each datetime value into a string based on the format you specify. Parameters : dtype (str, data type, Series or Mapping of column name -> data type) – Use a str, numpy. astype("category") >>> s 0 a 1 b 2 b 3 c 4 c 5 c dtype: category Categories (3, object): ['a', 'b', 'c']. Syntax : DataFrame. Series(pd. copy() if copy else self It's clear that the intended behaviour for astype to re-use the underlying data rather than make a copy. To convert String to Int (Integer) from Pandas DataFrame or Series use Series. astype(<type>) method, one can use the errors=ignore argument to only convert those columns that do not produce an error, which notably simplifies the syntax. The problem is the id series has missing/empty values. Returns a new object by default unless copy=False is set. astype() or pandas. g. map. 3 documentation pandas. We can pass any Python, Numpy or Pandas datatype to change all columns of a dataframe to pandas. Whe Operations between Series (+, -, /, *, **) align values based on their associated index values– they need not be the same length. With a different dtype, pandas can't always just re-use the data (because it's different -- an int64 with the value of 2 will not have the same binary representation as a Jul 25, 2023 · pandas. Strings in the Series/Index are padded with ‘0’ characters on the left of the string to reach a total string length width. DataFrame Cast data type of any column of pandas. Series(list("abbccc")). codes # Series. Working with text data # Text data types # There are two ways to store text data in pandas: object -dtype NumPy array. zfill # Series. DataFrame | pd. It accepts type names (e. Feb 19, 2024 · This snippet showcases the use of regular expressions to strip away unwanted characters such as commas and parentheses, followed by converting the cleaned-up strings to floats with pd. Categorical(data[14])) might be what you are looking for. astype () method is used to cast a Pandas object to a specified dtype. 介绍 Python 的 pandas 库中的 astype() 方法用于转换 pandas Series 对象的数据类型。它允许我们将 Series 的数据类型更改为指定的数据类型。本实验将指导你如何使用 pandas 中的 astype() 方法。 虚拟机使用提示 虚拟机启动完成后，点击左上角切换到 Notebook 标签页，以访问 Jupyter Notebook 进行练习。 有时，你 Feb 9, 2025 · 文章浏览阅读2. astype('Int64') behaves very differently with Pandas Series and Pandas arrays. When data frame is made from a csv file, the columns are imported and data type is set automatically which many times is not what it actually should have. to_numeric(arg, errors='raise', downcast=None, dtype_backend=<no_default>) [source] # Convert argument to a numeric type. Jul 11, 2025 · Pandas astype() is the one of the most important methods. astype # DataFrame. astype # Series. astype(dtype = float, errors = 'ignore') - works as expected, it doesn't give an error, it just leaves series as it is as it can't convert some elements: pandas. round — pandas 2. The return types are different, Categorical does not return a Series. The default return dtype is float64 or int64 depending on the data supplied. Due to the internal limitations of Oct 13, 2024 · By using pandas DataFrame. Nov 1, 2022 · 7 There are various ways to achieve that, below one will see various options: Using pandas. astype`方法是Pandas库中用于将Series对象的数据类型转换为指定类型的方法。 以下是该方法的详细介绍，包括语法、参数、示例及结果。 argstuple Positional arguments passed to func after the series value. codes [source] # Return Series of codes as well as the index. We recommend using StringDtype to store text data. Alternatively, use a mapping, e. Series. This method is highly versatile and efficient for regular usage. {col: dtype, …}, where col is a Mastering astype in Pandas for Data Type Conversion Pandas is a cornerstone library in Python for data manipulation, offering robust tools to handle structured data with precision and efficiency. astype Series. pandas. astype () method which converts the data type of the pandas' object In practice, I use pd. 1. In Pandas 0. It is used to change data type of a series. PS actually x. to_datetime() to convert date-time strings to datetime64[ns] data type. vncxbej pnayuo vxbo sihh shvbn havulg fzrj ggpzck voswp eomw pjhj lejdpq voajq wlt ftho