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The “ValueError: Trailing data” in Python is caused when there is extra or leftover data at the end of a code command. This can occur when using the “Fix” command, which is designed to correct any errors in the code. This error is commonly encountered when working with data sets, as it can be caused by incorrect formatting or missing values. In order to fix this error, it is important to carefully review the code and ensure that all data is properly formatted and complete before using the “Fix” command.
Fix in Python: ValueError: Trailing data
One error you may encounter when using Python is:
ValueError: Trailing data
This error usually occurs when you attempt to import a JSON file into a pandas DataFrame, yet the data is written in lines separated by endlines like ‘n‘.
The easiest way to fix this error is to simply specify lines=True when importing the data:
df = pd.read_json('my_data.json', lines=True)
The following example shows how to fix this error in practice.
How to Reproduce the Error
Suppose we have the following JSON file:
Now suppose we attempt to import this JSON file into a pandas DataFrame:
#attempt to import JSON file into pandas DataFrame
df = pd.read_json('Documents/DataFiles/my_data.json')
ValueError: Trailing data
We receive an error because the “Review” item in our JSON file contains n to represent endlines.
How to Fix the Error
The easiest way to fix this error is to simply specify lines=True when importing the data:
#import JSON file into pandas DataFrame df = pd.read_json('Documents/DataFiles/my_data.json', lines=True) #view DataFrame df ID Rating Review 0 A 8 Great movie.nI would recommend it. 1 B 5 Mediocre movie.nWould not recommend it. 2 C 3 Bad movie.nI would not recommend. 3 D 7 Decent movie.nI might recommend it.
Notice that we’re able to successfully import the JSON file into a pandas DataFrame without any errors.
If we’d like to remove the n endlines from the “Review” column, we can use the following syntax:
#replace n with empty space in 'Review' column
df['Review'] = df['Review'].str.replace('n', ' ')
#view updated DataFrame
df
ID Rating Review
0 A 8 Great movie. I would recommend it.
1 B 5 Mediocre movie. Would not recommend it.
2 C 3 Bad movie. I would not recommend.
3 D 7 Decent movie. I might recommend it.The n values are now removed from the “Review” column.
Additional Resources
The following tutorials explain how to perform other common operations in pandas:
Cite this article
stats writer (2024). What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?. PSYCHOLOGICAL SCALES. Retrieved from https://scales.arabpsychology.com/stats/what-is-causing-the-valueerror-trailing-data-in-my-python-code-when-trying-to-use-the-fix-command/
stats writer. "What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?." PSYCHOLOGICAL SCALES, 2 Jul. 2024, https://scales.arabpsychology.com/stats/what-is-causing-the-valueerror-trailing-data-in-my-python-code-when-trying-to-use-the-fix-command/.
stats writer. "What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?." PSYCHOLOGICAL SCALES, 2024. https://scales.arabpsychology.com/stats/what-is-causing-the-valueerror-trailing-data-in-my-python-code-when-trying-to-use-the-fix-command/.
stats writer (2024) 'What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?', PSYCHOLOGICAL SCALES. Available at: https://scales.arabpsychology.com/stats/what-is-causing-the-valueerror-trailing-data-in-my-python-code-when-trying-to-use-the-fix-command/.
[1] stats writer, "What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?," PSYCHOLOGICAL SCALES, vol. X, no. Y, ص Z-Z, July, 2024.
stats writer. What is causing the “ValueError: Trailing data” in my Python code when trying to use the “Fix” command?. PSYCHOLOGICAL SCALES. 2024;vol(issue):pages.