import pandas as pd import numpy as np !pip install openpyxl

arr = np.random.randint(low = 10, high = 100, size = (20, 10)) df = pd.DataFrame(data = arr)

df.shape

print(pd.ExcelWriter.__doc__)

with pd.ExcelWriter('myexcel.xlsx') as writer: df.to_excel(writer)

print(pd.DataFrame.__doc__)

classes = np.tile(['good', 'bad', 'neutral'], 100)[:20] classes = classes[np.random.randint(low = 0, high = 20, size = 20)]

df['Classes'] = classes

df.head()

df['Classes'], _ = pd.factorize(df['Classes'])

df.head()

df_2 = df.copy()[:15]

df.shape

df_2.shape

### Concatenation of dataframes pd.concat(objs =[df, df_2.sort_index(ascending = False)], axis = 1)

angles = np.array([90, 180, 270, 360]) angles = np.deg2rad(angles)

vector = np.random.randint(low = 10, high = 100, size = (10))

vsum = np.sqrt(np.sum(vector**2))

vsum

vsum*vsum/np.dot(vector, vector)

np.cos(angles)

### Merge dataframes pd.merge(left = df, right = df_2, how = 'outer')

all(['', 'dsfbujdfbvklfnbvk'])

any(df)

try_df = pd.concat(objs =[df, df_2.sort_index(ascending = False)], axis = 1)

all(try_df)

pd.isna(try_df)

try_df[pd.isna(try_df)]

try_df.fillna(value = 'Missing', inplace = True)

try_df

all(try_df)

pd.isna(try_df).sum()