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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Input/Output
Pandas objects are the main data structures used for collections of molecules. scikit-chem provides convenience functions to load objects into pandas.DataFrames from common file formats in cheminformatics.  
Reading files
The scikit-chem functionality is modelled after the pandas API.  To load an csv file using pandas you would call
Step1:  Analogously with scikit-chem
Step2:  Currently available
Step3:  scikit-chem also adds convenience methods onto pandas.DataFrame objects.
Step4:  Writing files
Again, this is analogous to pandas
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Python Code:
df = pd.read_csv('https://archive.org/download/scikit-chem_example_files/iris.csv', 
                 header=None); df
Explanation: Input/Output
Pandas objects are the main data structures used for collections of molecules. scikit-chem provides convenience functions to load objects into pandas.DataFrames from common file formats in cheminformatics.  
Reading files
The scikit-chem functionality is modelled after the pandas API.  To load an csv file using pandas you would call:
End of explanation
smi = skchem.read_smiles('https://archive.org/download/scikit-chem_example_files/example.smi')
Explanation: Analogously with scikit-chem:
End of explanation
[method for method in skchem.io.__dict__ if method.startswith('read_')]
Explanation: Currently available:
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pd.DataFrame.from_smiles('https://archive.org/download/scikit-chem_example_files/example.smi')
Explanation: scikit-chem also adds convenience methods onto pandas.DataFrame objects.
End of explanation
from io import StringIO
sio = StringIO()
df.to_csv(sio)
sio.seek(0)
print(sio.read())
sio = StringIO()
smi.iloc[:2].to_sdf(sio) # don't write too many!
sio.seek(0)
print(sio.read())
Explanation: Writing files
Again, this is analogous to pandas:
End of explanation
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