如何在 CSV 文件 Python 中将整数存储为字符串

Question

When trying to save some number as a string type in CSV file, then saving this file and reading it again, the file shows this saved data as a numpy.int64 instead of a string. How can this be solved so when reading the csv file it reads it as a string, not int?

Here is a Python script that describes this case

import pandas as pd

df = pd.DataFrame(columns=['ID'])

ID = '1'
df = df.append(pd.DataFrame([[ID]], columns=['ID']))
df.to_csv('test.csv', index=False)

"""
now the csv file looks like this:

ID
1
"""

df = pd.read_csv('test.csv')
print(df['ID'].iloc[0] == ID)  # this will print False
print(type(df['ID'].iloc[0]))  # this will print <class 'numpy.int64'>

Answer 1

The CSV file format doesn't distinguish between different data types. You have to specify the data type when reading the CSV with pandas.

df = pd.read_csv("test.csv", dtype=str)