Accessing Data

Intermediate Python for Finance

Kennedy Behrman

Data Engineer, Author, Founder

Account Balance

Pink Piggy Bank

Intermediate Python for Finance

Introducing lesson data

Bank Code Account# Balance
a BA ajfdk2 1222.00
b AAD 1234nmk 390789.11
c BA mm3d90 13.02
accounts
Intermediate Python for Finance

Access column using brackets

accounts['Balance']
Intermediate Python for Finance

Access column using brackets

accounts['Balance']
a 1222.00
b 390789.11
c 13.02

Name: Balance, dtype: float6

Intermediate Python for Finance

Access column using dot-syntax

accounts.Balance
Balance
a 1222.00
b 390789.11
c 13.02
Intermediate Python for Finance

Access multiple columns

accounts[['Bank Code', 'Account#']]
Intermediate Python for Finance

Access multiple columns

accounts[['Bank Code', 'Account#']]
Bank Code Account#
a BA ajfdk2
b AAD 1234nmk
c BA mm3d90
Intermediate Python for Finance

Access rows using brackets

accounts[0:2]
Intermediate Python for Finance

Access rows using brackets

accounts[0:2]
Bank Code Account# Balance
a BA ajfdk2 1222.00
b AAD 1234nmk 390789.11
Intermediate Python for Finance

Access rows using brackets

accounts[[True, False, True]]
Intermediate Python for Finance

Access rows using brackets

accounts[[True, False, True]]
Bank Code Account# Balance
a BA ajfdk2 1222.00
c BA mm3d90 13.02
Intermediate Python for Finance

loc and iloc

  • loc access by name
  • iloc access by position
Intermediate Python for Finance

loc

accounts.loc['b']
Bank Code AAD
Account# 1234nmk
Balance 390789

Name: b, dtype: object

Intermediate Python for Finance

loc

accounts.loc[['a','c']]
Bank Code Account# Balance
a BA ajfdk2 1222.00
c BA mm3d90 13.02
df.loc[[True, False, True]]
Bank Code Account# Balance
a BA ajfdk2 1222.00
c BA mm3d90 13.02
Intermediate Python for Finance

Columns with loc

accounts.loc['a':'c','Balance']
accounts.loc['a':'c', ['Balance','Account#']]
accounts.loc['a':'c',[True,False,True]]
accounts.loc['a':'c','Bank Code':'Balance']
Intermediate Python for Finance

Columns with loc

accounts.loc['a':'c',['Bank Code', 'Balance']]
Intermediate Python for Finance

Columns with loc

accounts.loc['a':'c',['Bank Code', 'Balance']]
Bank Code Balance
a BA 1222.00
b AAD 390789.11
c BA 13.02
Intermediate Python for Finance

iloc

accounts.iloc[0:2, [0,2]]
Intermediate Python for Finance

iloc

accounts.iloc[0:2, [0,2]]
Intermediate Python for Finance

iloc

accounts.iloc[0:2, [0,2]]
Bank Code Balance
a BA 1222.00
b AAD 390789.11
Intermediate Python for Finance

Setting a single value

Bank Code Account# Balance
a BA ajfdk2 1222.00
b AAD 1234nmk 390789.11
c BA mm3d90 13.02
accounts.loc['a', 'Balance'] = 0
Intermediate Python for Finance

Setting a single value

Bank Code Account# Balance
a BA ajfdk2 0.00
b AAD 1234nmk 390789.11
c BA mm3d90 13.02
accounts.loc['a', 'Balance'] = 0
Intermediate Python for Finance

Setting multiple values

Bank Code Account# Balance
a BA ajfdk2 1222.00
b AAD 1234nmk 390789.11
c BA mm3d90 13.02
accounts.iloc[:2, 1:] = 'NA'
Intermediate Python for Finance

Setting multiple columns

Bank Code Account# Balance
a BA NA NA
b AAD NA NA
c BA mm3d90 13.02
accounts.iloc[:2, 1:] = 'NA'
Intermediate Python for Finance

Let's practice!

Intermediate Python for Finance

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