pandas-selector 0.1.1

Pandas Selector

Simple, composable column selector for loc[], iloc[], assign() and others.

df_in = pd.DataFrame({"x": range(5)})
df = df_in.assign(y = df_in.x // 2)
df = df.loc[df.y <= 1]
df
#    x  y
# 0  0  0
# 1  1  0
# 2  2  1
# 3  3  1

from pandas_selector import DF
df = (df_in
      .assign(y = DF.x // 2)
      .loc[DF.y <= 1]
     )

df = pd.DataFrame({
    "X": range(5),
    "Y": ["1", "a", "c", "D", "e"],
})
df.loc[DF.y.str.isupper() | DF.y.str.isnumeric()]
#    X  y
# 0  0  1
# 3  3  D
df.loc[:, DF.columns.str.isupper()]
#    X
# 0  0
# 1  1
# 2  2
# 3  3
# 4  4

Similar projects for pandas

• pandas-ply

  • (-) stale(?), last change 6 years ago

  • (-) new API to learn

  • (-) Symbol / pandas_ply.X works only with ply_* functions

• pandas-select

  • (+) no explicite df necessary

  • (-) new API to learn

• pandas-selectable

  • (+) simple select accessor

  • (-) usage inside chains clumsy (needs explicite df):

    ((df
      .select.A == 'a')
      .select.B == 'b'
    )

  • (-) hard-coded str, dt accessor methods

  • (?) composable?

Development

Development is containerized with [Docker](https://www.docker.com/) to separte from host systems and improve reproducability. No other prerequisites are needed on the host system.

Recommendation for Windows users: install WSL 2 (tested on Ubuntu 20.04), and for containerized workflows, Docker Desktop for Windows.

The common tasks are collected in Makefile (See make help for a complete list):

• Run the unit tests: make test or make watch for continuously running tests on code-changes.

• Build the documentation: make docs

• TODO: Update the poetry.lock file: make lock

• Add a dependency:

  1. Start a shell in a new container.

  2. Add dependency with poetry add in the running container. This will update poetry.lock automatically:

     # 1. On the host system
     % make shell
     # 2. In the container instance:
     I have no name!@7d0e85b3a303:/app$ poetry add --dev --lock falcon

• Build the development image make devimage (Note: This should be done automatically for the targets.)