Pandas dataframe: truncate string fields

Question

I have a dataframe and would like to truncate each field to up to 20 characters. I\'ve been naively trying the following:

df = df.astype(str).apply(lambda x:         


        

Answer 1

you can use .str.slice() method:

Demo:

In [177]: df = pd.DataFrame({
     ...:   'a': pd.util.testing.rands_array(30, 10),
     ...:   'b': pd.util.testing.rands_array(30, 10),
     ...: })
     ...:

In [178]: df
Out[178]:
                                a                               b
0  Mlf6nOsC8S6vv8OxW5ZOWifg3EoqAb  XSGLdkaewwZlNeZ4uTTivi2nMQFc6S
1  0E4XCBaYFBTSalUMPGpXmke6dQGbkW  KlHuVhbNgQL9HLHYQq3fEdqEIciOhX
2  URODJeLA0uLvcKBEXPyrmnnNU40MDl  NaY8LURHjgmT1pRrDnbPAeLZq3ANaL
3  OYA1ahlwVtEVnDOAkZgxNkbvZ7W8Rf  mIzkeLhM7SqYH17vGDzL6DJjSYftGs
4  uFC1shE02UfxS0VhDASmF8vh9XxFYX  fQOxjDjFehTNT27seOtCAAPW0as9Up
5  Ja33vQym6L0Ko2Kcf8cg7OMBKMitg5  iGdCvYTyZlR23NeeTAjG1PoL8mWm3j
6  iNZdXaVpB4zXClxTLt738DY7i6xs6p  q9VKg5fZdItmUpZiQrR6XW5WHmd33l
7  WWnViRRMPkbXNQOHeqGmzETDpGPRl9  t3I8Ve3ybCJcXajF8pydnwNZQWslTN
8  5oMFy2PBe1zUIE3XdraMwlrd5MKcx2  gSLtgXJwiS1HugLORXherFT4l1k5QV
9  weV8BlyJrtRbWpSCxSbj8cSyZxusFR  ylLWort9o8mHWQQ3JB1Twb0xRbLhot

In [179]: df.apply(lambda x: x.str.slice(0, 20))
Out[179]:
                      a                     b
0  Mlf6nOsC8S6vv8OxW5ZO  XSGLdkaewwZlNeZ4uTTi
1  0E4XCBaYFBTSalUMPGpX  KlHuVhbNgQL9HLHYQq3f
2  URODJeLA0uLvcKBEXPyr  NaY8LURHjgmT1pRrDnbP
3  OYA1ahlwVtEVnDOAkZgx  mIzkeLhM7SqYH17vGDzL
4  uFC1shE02UfxS0VhDASm  fQOxjDjFehTNT27seOtC
5  Ja33vQym6L0Ko2Kcf8cg  iGdCvYTyZlR23NeeTAjG
6  iNZdXaVpB4zXClxTLt73  q9VKg5fZdItmUpZiQrR6
7  WWnViRRMPkbXNQOHeqGm  t3I8Ve3ybCJcXajF8pyd
8  5oMFy2PBe1zUIE3XdraM  gSLtgXJwiS1HugLORXhe
9  weV8BlyJrtRbWpSCxSbj  ylLWort9o8mHWQQ3JB1T