如何使用 Python 中另一个列表的元素类型创建列表

Question

I want to create a DataFrame with one instance per columns of my data and the type of that instance but I can't find a way to create a list of the types (in order to put it in the DataFrame).

Here is an example of what I want:

my_original_data = pd.DataFrame({'col1': [1,2,3],'col2':['Hello','foo','bar'],'col3':[dt.datetime(2000,1,1),dt.datetime(1999,12,2),dt.datetime(1950,5,3)]})

And I want a new DataFrame with first row = columns names, second row = first values, ie [1, 'Hello', dt.datetime(2000,1,1)] and third row = types of these values, ie [int, str, date].

How to create this last line?

Before to transform three lists into DataFrame, I tried

first_values = [my_original_data.loc[0,column] for column in df.columns]
types = [type(my_original_data.loc[0,column]) for column in df.columns]

It returns "TypeError: 'list' object is not callable". Same if I try

types = map(type,first_values)
list(types)

Answer 1

Try this:

cols = my_original_data.columns.tolist()
data = my_original_data.loc[0].tolist()
dtypes = list(map(type, data))

new_df = pd.DataFrame([[cols], [data], [dtypes]], columns=['df_desc'])

Answer 2

Similar to what u tried:

first = my_original_data.iloc[0,:].values
types = [type(my_original_data.iloc[0,column]) for column in range(len(my_original_data.columns))]

final_df = pd.DataFrame([first,types],index=['first','type'],columns = my_original_data.columns)