import glob
import pandas as pd
csv_files = glob.glob("path/to/folder/with/csvs/*.csv")
dfs = [pd.read_csv(filename) for filename in csv_files]

import pandas as pd
df = pd.read_csv("path/to/csv/file.csv")
df["Item_Identifier"].unique()array(['FDA15', 'DRC01', 'FDN15', ..., 'NCF55', 'NCW30', 'NCW05'], dtype=object)

from IPython.display import display_html
from itertools import chain,cycledef display_side_by_side(*args,titles=cycle([''])): # source: https://stackoverflow.com/questions/38783027/jupyter-notebook-display-two-pandas-tables-side-by-side html_str='' for df,title in zip(args, chain(titles,cycle(['</br>'])) ): html_str+='<th style="text-align:center"><td style="vertical-align:top">' html_str+="<br>" html_str+=f'<h2>{title}</h2>' html_str+=df.to_html().replace('table','table style="display:inline"') html_str+='</td></th>' display_html(html_str,raw=True)
df1 = pd.read_csv("file.csv")
df2 = pd.read_csv("file2")
display_side_by_side(df1.head(),df2.head(), titles=['Sales','Advertising'])
### Output

df = pd.DataFrame(dict(a=[1,2,3,None]))
df
df.dropna(inplace=True)
df

def findNaNCols(df): for col in df: print(f"Column: {col}") num_NaNs = df[col].isnull().sum() print(f"Number of NaNs: {num_NaNs}")
df = pd.DataFrame(dict(a=[1,2,3,None],b=[None,None,5,6]))
findNaNCols(df)# OutputColumn: a
Number of NaNs: 1
Column: b
Number of NaNs: 2

df = pd.DataFrame(dict(a=[10,20,30,40,50]))
square = lambda x: x**2
df["a"]=df["a"].apply(square)
df

df = pd.DataFrame(dict(a=["a","b","c"],b=[1,2,3]))
df_dictionary = dict(zip(df["a"],df["b"]))
df_dictionary{'a': 1, 'b': 2, 'c': 3}

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
sns.set()
import pandas as pd df = pd.DataFrame(dict(a=np.random.randint(0,100,100),b=np.arange(0,100,1)))
plt.figure(figsize=(15,7))
plt.subplot(1,2,1)
df["b"][df["a"]>50].hist(color="green",label="bigger than 50")
plt.legend()
plt.subplot(1,2,2)
df["b"][df["a"]<50].hist(color="orange",label="smaller than 50")
plt.legend()
plt.show()

from scipy.stats import ttest_rel data = np.arange(0,1000,1)
data_plus_noise = np.arange(0,1000,1) + np.random.normal(0,1,1000)
df = pd.DataFrame(dict(data=data, data_plus_noise=data_plus_noise))
print(ttest_rel(df["data"],df["data_plus_noise"]))# Output
Ttest_relResult(statistic=-1.2717454718006775, pvalue=0.20375954602300195)

df1 = pd.DataFrame(dict(a=[1,2,3],b=[10,20,30],col_to_merge=["a","b","c"]))
df2 = pd.DataFrame(dict(d=[10,20,100],col_to_merge=["a","b","c"]))
df_merged = df1.merge(df2, on='col_to_merge')
df_merged

from sklearn.preprocessing import MinMaxScaler
scaler = MinMaxScaler()
scores = scaler.fit_transform(df["a"].values.reshape(-1,1))

df.dropna(subset=["col_to_remove_NaNs_from"],inplace=True)

df = pd.DataFrame(dict(result=["Pass","Fail","Pass","Fail","Distinction","Distinction"]))
pass_index = (df["result"]=="Pass") | (df["result"]=="Distinction")
df_pass = df[pass_index]
df_pass

import matplotlib.pyplot as plt df = pd.DataFrame(dict(a=[10,20,50,10,10],b=["A","B","C","D","E"]))
labels = df["b"]
sizes = df["a"]
plt.pie(sizes, labels=labels, autopct='%1.1f%%', shadow=True, startangle=140)
plt.axis('equal')
plt.show()

def change_to_numerical(x): try: x = int(x.strip("%")[:2]) except: x = int(x.strip("%")[:1]) return x df = pd.DataFrame(dict(a=["A","B","C"],col_with_percentage=["10%","70%","20%"]))
df["col_with_percentage"] = df["col_with_percentage"].apply(change_to_numerical)
df