Fixing format in floating point precision docs

Author: Jessica Oraegbu

doc/source/user_guide/io.rst

@@ -1686,25 +1686,21 @@ The conversion process is not always guaranteed to be accurate because small dif
 ``df = pd.read_csv('file.csv', float_precision='round_trip')`` allows for floating point precision to be specified when reading from the CSV file. This is guaranteed to round-trip values after writing to a file and Pandas will read the numbers without losing or changing decimal places.
 
 .. ipython:: python
-
+   from import StringIO
    import pandas as pd
-   import os
 
    x0 = 18292498239.824
    df1 = pd.DataFrame({'One': [x0]}, index=["bignum"])
 
-   df1.to_csv('test.csv', float_format='%.17g')
-   df2 = pd.read_csv('test.csv', index_col=0, float_precision='round_trip')
+   csv_string = df1.to_csv(float_format='%.17g')
+   df2 = pd.read_csv(StringIO(csv_string), index_col=0, float_precision='round_trip')
 
    x1 = df1.iloc[0, 0]
-   x2 = df2['One'][0]
+   x2 = df2.iloc[0, 0]
 
    print(f"x0 = {x0}; x1 = {x1}; Are they equal? {x0 == x1}")
    print(f"x0 = {x0}; x2 = {x2}; Are they equal? {x0 == x2}")
 
-
-   os.remove('test.csv')
-
 Writing a formatted string
 ++++++++++++++++++++++++++