Pandas: Actual Applications

 

pandas.DataFrame.replace

http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.replace.html?highlight=replace#pandas-dataframe-replace

df = df.replace('无', np.nan)

pandas.DataFrame.applymap

http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.applymap.html#pandas-dataframe-applymap

df = df.applymap(lambda x: str(x).strip())

pandas.DataFrame.rename

http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.rename.html?highlight=rename#pandas-dataframe-rename

*

df.columns = ['a', 'b', 'c']

# using keyword arguments to clarify your intent:
df = df.rename(columns={'A': 'a', 'B': 'b', 'C': 'c'}) 
# axis-style: 
df = df.rename(str.lower, axis='columns')