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在这篇文章中,我们将看到在 Pandas Dataframe 中将浮点数转换为字符串的不同方法? Pandas Dataframe 提供了更改列值数据类型的自由。我们可以将它们从 Integers 更改为 Float 类型,Integer 更改为 String,String 更改为 Integer,Float 更改为 String 等。 将浮点数转换为字符串的三种方法: 方法一:使用DataFrame.astype()。 用法: DataFrame.astype(dtype, copy=True, errors=’raise’, **kwargs)这用于将 pandas 对象转换为指定的 dtype。此函数还提供将任何合适的现有列转换为分类类型的函数。 范例1:将一列从浮点数转换为字符串。 Python3 # Import pandas library import pandas as pd # initialize list of lists data = [['Harvey', 10, 45.25], ['Carson', 15, 54.85], ['juli', 14, 87.21], ['Ricky', 20, 45.23], ['Gregory', 21, 77.25], ['Jessie', 16, 95.21]] # Create the pandas DataFrame df = pd.DataFrame(data, columns = ['Name', 'Age', 'Marks'], index = ['a', 'b', 'c', 'd', 'e', 'f']) # lets find out the data type # of 'Marks' column print (df.dtypes)输出: 现在,我们将“Marks”列的数据类型从 ‘float64’ 更改为 ‘object’。 Python3 # Now we will convert it from # 'float' to 'String' type. df['Marks'] = df['Marks'].astype(str) print() # lets find out the data # type after changing print(df.dtypes) # print dataframe. df输出: 范例2:将多于一列从浮点数转换为字符串。 Python3 # Import pandas library import pandas as pd # initialize list of lists data = [['Harvey.', 10.5, 45.25, 95.2], ['Carson', 15.2, 54.85, 50.8], ['juli', 14.9, 87.21, 60.4], ['Ricky', 20.3, 45.23, 99.5], ['Gregory', 21.1, 77.25, 90.9], ['Jessie', 16.4, 95.21, 10.85]] # Create the pandas DataFrame df = pd.DataFrame(data, columns = ['Name', 'Age', 'Marks', 'Accuracy'], index = ['a', 'b', 'c', 'd', 'e', 'f']) # lets find out the data type # of 'Age' and 'Accuracy' columns print (df.dtypes)输出: 现在,我们将“Accuracy”和“Age”列的数据类型从 ‘float64’ 更改为 ‘object’。 Python3 # Now Pass a dictionary to # astype() function which contains # two columns and hence convert them # from float to string type df = df.astype({"Age":'str', "Accuracy":'str'}) print() # lets find out the data # type after changing print(df.dtypes) # print dataframe. df输出: 方法二:使用Series.apply()。 用法: DataFrame.apply(func, axis=0, raw=False, result_type=None, args=(), **kwds)此方法允许用户传递一个函数并将其应用于 Pandas 系列的每个值。 例:将 DataFrame 的列从浮点数转换为字符串。 Python3 # Import pandas library import pandas as pd # initialize list of lists data = [['Harvey.', 10.5, 45.25, 95.2], ['Carson', 15.2, 54.85, 50.8], ['juli', 14.9, 87.21, 60.4], ['Ricky', 20.3, 45.23, 99.5], ['Gregory', 21.1, 77.25, 90.9], ['Jessie', 16.4, 95.21, 10.85]] # Create the pandas DataFrame df = pd.DataFrame(data, columns = ['Name', 'Age', 'Percentage', 'Accuracy'], index = ['a', 'b', 'c', 'd', 'e', 'f']) # lets find out the data # type of 'Percentage' column print (df.dtypes)输出: 现在,我们将“百分比”列的数据类型从“float64”更改为“对象”。 Python3 # Now we will convert it from # 'float' to 'string' type. df['Percentage'] = df['Percentage'].apply(str) print() # lets find out the data # type after changing print(df.dtypes) # print dataframe. df输出: 方法3:使用Series.map()。 用法: Series.map(arg, na_action=None)此方法用于映射来自具有相同列的两个系列的值。 例:将 DataFrame 的列从浮点数转换为字符串。 Python3 # Import pandas library import pandas as pd # initialize list of lists data = [['Harvey.', 10.5, 45.25, 95.2], ['Carson', 15.2, 54.85, 50.8], ['juli', 14.9, 87.21, 60.4], ['Ricky', 20.3, 45.23, 99.5], ['Gregory', 21.1, 77.25, 90.9], ['Jessie', 16.4, 95.21, 10.85]] # Create the pandas DataFrame df = pd.DataFrame(data, columns = ['Name', 'Age', 'Percentage', 'Accuracy'], index = ['a', 'b', 'c', 'd', 'e', 'f']) # lets find out the data # type of 'Age' column print (df.dtypes)输出: 现在,我们将“Age”列的数据类型从“float64”更改为“object”。 Python3 # Now we will convert it from 'float' to 'string' type. # using DataFrame.map(str) function df['Age'] = df['Age'].map(str) print() # lets find out the data type after changing print(df.dtypes) # print dataframe. df输出: |
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